I agree that all known DesignIDs should be available to someone to wants to select a part by number, but the duplication of identical descriptions in a descriptive list is frustrating to users who don't care about the existence of aliases. Randomly choosing an alias instead of a base part unnecessarily complicates model files. LDMakelist helps to solve that (with the appropriate options) by excluding aliases from parts.lst.
Adding alias numbers into the base part as metadata is not a restriction of the LDraw file format - we can invent whatever meta-statements would be useful. The main problem is lack of support for such extensions in tools that are no longer in development (e.g. MLCad).
However, adding the alias numbers to the base part would mean that we would be forever re-issuing parts when a new alias is released. Managing the existence of an alias as a separate file has strong benefits to me from a release management perspective. Support questions like "why is this model not finding this part" are much easier to answer with "that part (file) was not released until update YYYY-XX" than "well, that's really an alias of part NNNN and the relationship between the two was not established until the version of NNNN released in update YYYY-XX". So, I'd much prefer the unit of release control to be the Design ID.
Adding alias numbers into the base part as metadata is not a restriction of the LDraw file format - we can invent whatever meta-statements would be useful. The main problem is lack of support for such extensions in tools that are no longer in development (e.g. MLCad).
However, adding the alias numbers to the base part would mean that we would be forever re-issuing parts when a new alias is released. Managing the existence of an alias as a separate file has strong benefits to me from a release management perspective. Support questions like "why is this model not finding this part" are much easier to answer with "that part (file) was not released until update YYYY-XX" than "well, that's really an alias of part NNNN and the relationship between the two was not established until the version of NNNN released in update YYYY-XX". So, I'd much prefer the unit of release control to be the Design ID.
Chris (LDraw Parts Library Admin)