Layer Naming Syntax – The Final Say?

With C3D, it seems that the big push is toward the NCS layer naming system. What is NCS and of what benefit is it to you? The following is written using NCS 3.0 as the basis. Find out more after the jump.

Around the world there are quite a few CAD Standards. The ISO (International Organization for Standardization) has a layer naming format (ISO 13567). The BSI (British Standards Institution) also has a layer naming syntax which is pretty much just ISO’s (BS 1192) and in the states there is the NCS layer naming syntax. NCS stands for National CAD Standards and although it is primarily known for its Layer Naming syntax, there is MUCH more to it than that. The NCS got its start a few years back by pulling together the CAD Layer Guidelines from The American Institute of Architect’s, the Construction Specification Institute’s Uniform Drawing System, and the CADD/GIS Center’s Plotting Guidelines, as publicized by the U.S. Department of Defense CAD/GIS Technology Center.

See there! The layer naming comes from Architects and as all Civil guys know, nothing good comes from Architects.

Well there is always an exception to the rule and as we investigate this naming format more fully, I think you will agree with me how versatile it really is.

The Concept

image The concept behind the NCS layer naming format is the organizational structure called the ‘tree structure’. One of the most common examples of the ‘tree structure’ is found in Windows Explorer. Files (data) stored on a computer are not organized in this method (ever heard of defrag?) but the presentation to us is the ‘tree structure’. You have drives, main folders, and then sub-folders and sub-folders of sub-folders, etc. The same concept is applied to the naming of a layer.

The Format

Just as you have drives, we have disciplines. EVERY layer in a drawing belongs to a discipline just like every file must have a drive location. Then every layer must belong to a major group just as every file must have a name. Let’s look at this more fully.

Discipline Designators

A discipline designator is a one or two letter designator that defines the discipline that the layer belongs to. Remember, EVERY LAYER in a drawing belongs to a discipline. Since the NCS is established for every AEC discipline, then there are many designators that we will never use. The following figure organizes the most common disciplines into a hierarchy.

Discipline Hierarchy

Major Discipline Designator





Hazardous Materials


















Fire Protection














Other Disciplines


Contractor/Shop Drawings



Minor Discipline Designators

Although the Major Discipline designator defines which discipline, I prefer to also use the optional Minor Discipline Designator. The reason is then you can control not only what type of work each layer belongs to (grading, environmental/erosion, site, etc.) but also for survey’s we can quickly tell you what kind of survey the layer belongs to (GIS, Field shot, aerial, etc.).

Minor Discipline Designators


Civil Demolition


Civil Environment


Civil Grading


Civil Roadway


Civil Site


Civil Utilities


Civil Junk


Civil Miscellaneous


Aerial Survey


Field Survey


Digital Survey


Survey Junk


Survey Miscellaneous


Major Group

After we have defined the discipline for the layer, now we have to assign the layer a name. To do this we group common layers together starting with what is referred to as the Major Group. Just as you have Major Folders (C:\Windows, C:\Program Files\, etc.) you have types of construction that can be grouped together (CS-ROAD, CG-TOPO, CU-SSWR). First rule of all groups, major and minor, is that they are ALWAYS EXACTLY FOUR CHARACTERS IN LENGTH. This provides legible consistency and controls the order of these layers in the layer dialog box (let alone great automation potential). The NCS defines many Major Groups and if you strictly adhere to the NCS, you are not allowed to create your own but what we are reviewing is the naming format, not so much rules. As a popular movie quote says, “They are more like guidelines anyway”.

Just as the drive and the file/folder name are separate so the Discipline designator and the major group are separated using a hyphen “-“.

Minor Groups

Within a tree structure, you can be as organized or as cluttered as you wish past these two first stages (Drive and file name). The same applies to the NCS layer naming format. If we want to place all the roadway objects (edge of road, centerline, curb lines, etc) on one layer we can (CS-ROAD). Of course, the best practice is to break these up a bit. However, they all still belong to the same major group of CS-ROAD (Civil, Site, Road). Therefore, the purpose of minor groups (CS-ROAD-ASPH, CS-ROAD-CNTR, CS-ROAD-CURB).

You can even get more organized than one minor group. For example, you want to separate the face of curb and back of curb on different layers. However, both the back and the face are part of the CURB group, right? So you would have CS-ROAD-CURB-BACK and CS-ROAD-CURB-FACE. Obviously, just as each sub-folder name is separated from the parent folder so each group is separated from the other with a hyphen “-“.

Note two other things:

  1. All layers are in uppercase.

Are you starting to see the power of the format?

Status Fields

Just as a file can have separate properties from the folder it belongs to (i.e., read-only) so a layer that belongs to a specific group can be in a different status from the rest of the group.


To be demolished








By others (NIC)


Phase numbers

For example, you have the field survey file showing a road curb. However, some of that curb is to be removed. The curb that is to be removed is still part of the major group of road and the minor group of curb but its status has changed. It is going to be demolished. Therefore, the layer name will simply have the status “D” added to the end.

Some points to remember about a status field:

  1. It is not required but is only added when necessary. For example, the status field “E” is not required for each survey layer. However, for an existing profile grade this would be appropriate (CK-GRAD-E / Civil, Miscellaneous, Grade Line, Existing).
  2. A Status Field is always found at the end of the layer.

Just as all other parts of a layer are separated from one another by a dash so the status field is separate from the group with a hyphen “-“. USE ONLY THE STATUS FIELDS PROVIDED.


Let’s look at a few examples of this format at work. For a proposed asphalt road edge layer we would have the following:


Notice that the minor group actually defines the material used for the road. If this does not matter we can use “EDGE” as a minor group. However, it is encouraged to use the material groups. For example, we can have the layer above and the layer below in one drawing.


More complex options

Road, Drives, and Parking Lots versus Pavement

With a drawing containing a proposed concrete parking lot, a proposed gravel drive, and a proposed asphalt road it gets a little more complicated. The question comes down to whether or not you want/need to separate each infrastructure on its own group or not. If the answer is yes, then you would have three major groups spreading the layers out in the pulldown but providing flexibility if you need to freeze objects from one major group but not the other. Let’s look at the edge of pavement layers for each.

The parking lot edge of concrete pavement layer:


The drive edge of gravel pavement layer:


The road edge of asphalt pavement layer:


If the answer to the above question is no, each infrastructure does not need to be on its own major group then you would still have three layers but under one major group – the Pavement major group.

The parking lot edge of concrete pavement layer:


The drive edge of gravel pavement layer:


The road edge of asphalt pavement layer:


The last option is if you did not want/need to separate the pavement materials into separate layers than the layer for all would be as follows:


Paved walks

Another example where some might get confused is that the sidewalk could fall under the pavement major group or the sidewalk major group. However, again applying some common sense and forethought about that specific project will help us know which major group the sidewalk would fall under. If for any reason the sidewalk NEEDED to be split from the rest of the pavement group then by all means use the sidewalk major group. That is what it is there for. Nevertheless, more often than not the sidewalk is a portion of the paved areas shown (concrete pads, concrete sidewalks, etc.). In these more common cases the concrete sidewalk would be found on the CS-PVMT-CONC layer. In rare cases where the sidewalk is a major component of the project (i.e., a park) and needs to be separated from the rest of the paved areas then the concrete sidewalk would be found on the CS-SWLK-CONC layer.

Just One Benefit

There are so many benefits to this formatting but let us look at just one often overlooked benefit – layer filtering.

In AutoCAD 2005, the Layer Properties Manager dialog box was revamped and the layer filtering tools were emphasized in this new layout. Yet, many of us (including me) still do not use them to the full. A layer filter is exactly that – a way to filter layers based upon properties.

To create a new filter click on the “New Property Filter” button in the top left of the layer properties manager dialog. A new layer filter properties dialog will pop up. Let’s create a demolition filter based upon the layer naming format we have established. Since demolition is a status of a group and is always found at the end of a layer, we can enter in the name section of the filter the “all” wildcard (*), the separator (the hyphen “-“), and then the demolition status field (“D”).

If you hit okay then the filter will show up in the left side of the layer properties manager and will be current only showing to you the demolition layers found in the drawing.

You can get even more specific than that. Say that there are two survey files being referenced in and you want to see only the topography layers for the field shot survey. We would add the “all” wildcard at the beginning since we do not know what the xref names are. Follow the wildcard with the pipe “|” that is used by AutoCAD to separate the xref name from the layer name. Then the “VF” discipline designator for field shot survey, the hyphen, and the “TOPO” major group. It should look like this “*|VF-TOPO”.


Some points for review:

  1. EVERY layer in a drawing has a discipline designator and a major group just as every file has a name and a drive.
    • The discipline designator can be two characters – the major and minor designator.
  2. Every layer shall be created in all caps. The reason is that since 2002, a smaller case layer name and an upper case layer name are TWO DIFFERENT layers. To avoid multiple copies of layers, confusion and to keep consistency, we put all layers in caps.
  3. Be Consistent
  4. EVERY group is EXACTLY FOUR CHARACTERS in length
  5. Each group is separated from the other using a hyphen “-“
  6. The status field ALWAYS goes at the end of the layer
  7. Use common sense. I shouldn’t have to say it but just think about the life of the layer/project/drawing before you create the layer. This helps know what major group to place objects on especially when there are multiple groups the objects could belong to.

This layer naming system is used around the world. In fact, it is the layer naming format encouraged and built into the Autodesk software. No other CAD Standard (ISO or BS) is so widely accepted nor integrated into AutoCAD.

Now for the comments!


  1. Oh boy, This could be a big Can ‘O Worms.
    I’ll try to keep my comment quick and dirty. Maybe a tad bit more dirty. 🙂

    I’m going to take it from your last sentence and expound from there.
    The “English” language is so much more widely accepted by most autocad users around the world. So my argument is… NCS needs to spell out the layer name.
    I do believe in the use of prefixes to organize disciplines and phases. However, the rest of the layer can be spelled out.

    The NCS was first published in 1999, before that AIA, and CSI created the standard naming. And this was when there were layer limitations.
    We haven’t been limited to the 8 character name length for over 15 years. I’m guessing this whole abbreviation thing had started because of the software limitations at the time. I remember 15 years ago looking at a layer abbreviation and then looking in a 40 page cad manual to see what that layer was used for. That’s one of the main reasons it hasn’t been adopted by every firm. It’s very inefficient. And this causes users not to follow the standards because it’s frustrating not to look at a layer and instantly know what it’s used for.

    Now for everyone that reads this blog, we can pretty much get through some deficiencies and make things work and accept what’s required while still being efficient. But the majority of users have trouble dealing with thinking about what layer should something go on. Most of you know this is not an exaggeration.

    Take the minor designations “CJ” and “CK”. Are you kidding me “Civil Junk” and “Civil Misc.”. These types of layers should not even be an option to users.

    I agree with some of the benefits and the ease of automation in the number of characters, but that only relates to a select few power users, not the majority of users that are only in production and design mode.

    If it made sense and was efficient for everyone, it would have already been adopted by everyone.

    • By all means I am expecting comments and really it is so that all of us walk away a bit more educated (and hopefully not a bit more mad 🙂 )

      I think that the 4 character group length comes from more having consistency and providing for greater automation control. The majority of users benefit from the automation control provided by the few power users.

      As regards what layer something should go on, I think that is the biggest power of NCS as well as its biggest downfall. Seeing that the NCS format allows for flexibility means that objects are not automatically assigned to a layer. Time for education, education, education. Is this feasible? That is what each company deals with.

      Since every layer MUST belong to a discipline designator and if you choose to use a minor discipline designator, then what minor discipline designator do you use for your viewport? Or for your titleblock, north arrow, scale, etc.? I think that is where the CK and CJ minors come in handy. Again consistency is the key to the format so if you use minors ALL layers in the drawing use minor discipline designators.

      I have worked with quite a few company standards that had layer names that could not be deciphered. However, the NCS standard groups can EASILY be read by anyone in the field without a book.

      Let the comments continue 🙂

      • Jason Haagen says:

        Titleblocks and Mview’s are General in the sense that every discipline uses them. So I have always put them under the “G-” designation.

        Additionally you can also add descriptions to your layer names to help specify what they mean should not be able to infer from an abbreviation. I have always used an excel file to add descriptions / find & replace a large group of layer names (since Autodesk hasn’t incorporated that functionality yet). I’ll share it if you like.

  2. Matt Anderson says:

    Its a great guideline that helped us transform, but culturally, our firm always took Status first

    EX –
    PR –
    FU –

    and our Drawing spefic stuff alway well to the DWG- status…

  3. Jeremy Nelson says:

    I have been going around the NCS with various clients as well as implementing a new company layer standard with the introduction of Civil 3D. I still have a problem with the NCS not having all the layers a Civil group needs, and also needing to have a subscription fee for updates to use something that benefits everyone. For this reason I have been steering people to using the Army Corp of Eng. provided materials for a standard. Not to mention that the AEC standard is intended to be used in Microstation as well at AutoCAD.

    From this publish document ( it is committed to the NCS and participates on the NCS Steering committee to implement its standards into it. Also they provide a 477 page PDF documenting, templates, pen tables, Linetypes, Details, and most anything you need to get a standard running. ( .

    I have gotten some grief from others using the AEC materials as being not NCS, but it is for the most part and then some. I also have been working on some Veteran’s Affairs projects, and looking at the standards they have, the VA falls right in line with what the AEC has in it with a few exceptions that the VA wants amended.

    Did I mention that all this is published on the site, and is downloadable. (2,000± premade files ready to use)
    “Approved for public release; distribution is unlimited.” – ERDC/ITL TR-09-2, July 2009

  4. Jeremy,
    Thanks for sharing the COE links. I was going to include a little about that but figured my post was long enough 🙂

  5. Neil Wilson says:

    I don’t take your post as an endorsement of the NCS Josh. It is impotant to be familiar with the standard even if we don’t use it.

    Being CAD manager for my company I’ve considered the NCS and decided it was not all that well suited for us. We rarely have to integrate our cad files with other disciplines (we are a civil shop) so the discipline code was just unnecessary baggage. If someone wants to add codes to our layers it is easy to add them. It is NOT easy to remove them.

    Also I don’t like the temporal (status) code being appended to the end of a layer in the standard. When we distribure our cad data to other consultants or agencies they often request that all the data be compiled into one drawing, and sometimes we need to mix existing proposed, future and/or asbuilt data in a drawing as well. Thus we include a status code in all of our layers. It immediately follows the primary classifier. If we put it at the end as per the NCS we would have the 2,3,4 or more layers of the same primary class all listed together which is a strain on the eyes when browsing for a layer.

    In spite of it’s shortcomings the structure of the NCS layer convention provided a good framework for our system.

    I also agree wholeheartedly with Josh that layer names need to be intuitive so that a user can readily recognize them without having to refer to a legend, though I wouldn’t go so far as to say they need to be entirely spelled out. Studies have demonstrated that we can read words with missing vowels handily, so abbreviations work well in many cases.

  6. Sam Holderscape says:

    Thank you for a great article on NCS.

    Having worked through CAD standards for a couple of previous employers, NCS is very welcome and should have been started 2 decades ago, when CAD was still a new concept to many.

    I definitely agree with Jeremy Nelson that the DoD’s AEC standards are an inexpensive way to learn and adopt NCS standards for smaller companies and students. However, large companies need to bite the bullet and buy the package for their CAD managers and get involved in the development and updates of the standard.

    There will always be problems with any standard, and NCS has it’s share. My 2 main issues with NCS are Status Fields and Labeling. Tagging the end of the layer name with E, D, T, F, etc. really make it hard to quickly turn these off and on as a group without programing and keeping a specific filter up to date. As with the way most of us older users learned, existing and proposed have always been the most important designation, not the least important. Also, not addressed in this document is labeling, or text layers. I haven’t read the latest version of NCS, but unless changes have been made, having all your labeling and dimensions under C-ANNO… or C-LABL… or the like does not make complete sense to me. Personally, I like to have my labels associated with the representative layers, like C-ROAD-DIMS or C-EROS-TEXT, so that when I freeze or turn off the main layer, C-ROAD, I can also easily locate and freeze or turn off the associated text layer, C-ROAD-DIMS.

    Of course if we are using Civil 3D like most of us were taught, we’re putting all of our design on just a handfull of layers and using styles to turn things on and off anyway. LOL!

    Once again, thanks for a great article!

  7. DENNIS SCHMIDT, P. ENG. says:

    I am in the process of starting up a civil division in a multidisciplinary firm, and the NCS is helping me a lot. I’ve been places where there was an informal standard and it can go to hell real fast if you don’t have someone paying attention to those details. I htink that, if you at least follow a standard, you don’t get near as many questions about where to find linework for a certain feature. Also, a person can use the layer translator later on to consolidate layers for those who want everything (for example, all curbs) on one layer as opposed to several. I also use the description area on the layer manager to describe what is on said layer to further eliminate confusion.

  8. DENNIS SCHMIDT, P. ENG. says:

    oh, on another topic: I am wondering how I can create a label style with text and a line over top of the text that flips when I pull the text. I set up one with a line, but I have to leave dragged state as composed, and my leader doesn’t flip to the other side when I do that, and the overscore (%%o) doesn’t overscore the text in the label, it just shows up as %%o followed by text. Any ideas?

  9. John Mayo, PE says:

    Good post Josh. We were never big fans of NCS layer name conventions but at least now I better understand why we don’t use them. 😉