Customizing the metamodel : Customizing the repository metamodel: SAPROPS.CFG and USRPROPS.TXT : Rules for editing USRPROPS.TXT
  
Rules for editing USRPROPS.TXT
The function of USRPROPS.TXT in an encyclopedia is to modify properties already defined in SAPROPS.CFG, or to add properties not found in SAPROPS.CFG.
When System Architect creates a new encyclopedia, the USRPROPS.TXT file from the executable directory is copied into the new subdirectory.
SAPROPS.CFG things you cannot override with USRPROPS.TXT
There are a few important elements that you cannot change:
You cannot modify CHAPTER and GROUP names that are predefined by System Architect in SAPROPS.
You cannot remove a label which has been defined in SAPROPS. However you can modify the text to be displayed in the label.
You cannot remove a LIST or LISTONLY reference which has been defined in SAPROPS. However you can modify the text to be displayed in the list.
If a property is new (that is, it is not declared in SAPROPS.CFG), it may not be KEY. Otherwise, System Architect emits a warning and ignores the attempt to make the property a key.
If a property is not new (that is, it is declared in SAPROPS.CFG), a different edit type may not be used. Otherwise, System Architect emits a warning and ignores the attempt to change the edit type.
If a property is not new and is a reference property (OneOf, ListOf, ParmOneOf, and so on), the type of the referent may not be changed. Otherwise, System Architect emits a warning and ignores the attempt to change the referent type.
If a property is not new and is a reference property, the keyed by clause may not be changed. Otherwise, System Architect emits a warning and ignores the attempt to change the keyed by clause.
If a property is not new and is not a key, the user may not attempt to make it a key. Otherwise, System Architect emits a warning and ignores the attempt to make a non-key property key.
If a property is not new, the user may not attempt to shorten its length. Otherwise, System Architect emits a warning and ignores the attempt to shorten the length.
If a property is not new, the user may not attempt to make it edited ASGRID if it was not so originally. Otherwise, System Architect emits a warning and ignores the attempt.
In general, there are no restrictions on what the user may do with the user definitions (USER1 through USER150). The only exception is cited next.
If the keyword ASGRID is used for a property, it must have an edit type which is either ListOf or ParmListOf. Otherwise, System Architect emits a warning and ignores the ASGRID keyword.