The default keynoting data provided in Revit LT is based on the 1995 Construction Specification Institute (CSI) Master format system, which uses 16 divisions to organize construction process and materials. This is a widely used system in the United States. See .
A more recent version of this system has not yet seen wide-spread adoption. This newer version is based upon 50 divisions and was introduced in 2004. Support for this new format can be accomplished by adding the additional divisions to the default keynote data files as needed. See .
This system is most effective when objects that are used throughout a project are already assigned their respective keynote values. When these values are not supplied, you can assign a value as you place a keynote tag. Materials, system and component families, and detail components can have keynote parameters entered in advance.