Thank you for the suggestion, but what should we do if several manufacturers make the same part? I think, you can add custom additional field for certain components only and put manufacturer part numbers there.
I see DB-15 connector in standard libraries, but it has 2 rows, but as I know VGA connector has 3 rows by 5 pins. I'm afraid, you should create custom pattern in Pattern editor.
One problem is that, for example, two connectors may look practically the same but have subtle differences in their pattern. It that case, it would be nice to know at least one manufacturer (and part number) for which the pattern was built. Even in the case where really equivalent parts are available from two or more manufacturers, it would be helpful to have a pointer to at least one of those. Often on manufacturers' web sites you can find a list or search for a part that is equivalent to some other manufacturer's part number. So for example if the component (or pattern, perhaps) shows part number xxx.yyy from manufacturer A, if I go to manufacturer B's website and search for xxx.yyy, it may say that www.zzz
from B is equivalent. Without having that xxx.yyy number, it is like looking for a needle in a haystack, especially with connectors.
Of course, you already do deal with this problem for integrated circuits. In that case, for example, I can find the LM/MC 79L05 listed under several different manufacturer's libraries. That seems like a reasonable way to take care of the problem. I guess I did find in DipTrace that I can search for all components that use a particular pattern, so if there were component libraries for each of several different connector manufacturers (e.g. Amphenol, AMP, Molex, FTI, Samtec...), I could then find specific parts that used any particular pattern. In fact, I've started to build such component libraries for my own use, and posted the start of a Samtec one to the forum. As you say, I always have the option to build my own patterns, which I'm happy to do, but it does take time and if I can save that time by re-using an existing pattern, I'm even happier than if I have to build it myself!
I don't need the VGA DB-15 right now, but if I do before someone else builds one, I'll try to upload it so others can have it too.