Layer names are the first step in a CAD Standard. Most firms start here and move forward with other areas. I have seen some CAD Standards that are just a layer list and they stop there. Following the AIA and the NCS will put you in line with most firms.
Here is some wording that starts to address layer standards:
The National CAD Standard & AIA CAD Layer Guidelines are to be used on all projects as they apply.
The base nine colors (i.e. 1-9) should be used for each discipline’s base layer names. These colors have names as well as color numbers. Other colors can be used as the disciplines define their layers.
The format of layer names must follow the two-four-four-four-one standard, No layer name can exceed this convention. The preferred method is to use just one character for the discipline designator.
The last character in the layer name, called the status field, will be modified to allow for scale factor designations in the layer name (i.e. ¼” will be 0048, ½” will be 0024; ex. A-anno-text-0048 is a ¼” text layer) This field code will be used for all scale-specific layer names.
Specific layer names will define settings for linetype, color & line type. These will be broken out to allow for specific use.
All graphics will be created “ByLayer”. No assignment of Linewieght (LWT) to Layers will be used. Everything is drawn using default Line wieghts and plots bylayer.
Keep layer names as short and simple as possible. To do this use the base layer name for all objects that pertain to the entity you are creating. Break out layers only as needed.
An Appendix can be added that has layer names defined more specifically to each discipline.