The problem is, with a library such as rlc, you can imagine it could get incredibly vast if you tried to cater for every possible variant of part within the library. It's possible but it would be massive and unwieldy and most people would only use about 0.0001% of the library. Actually, as with most libraries, it's probably better not to just use rlc as is and create something which works for you as there are so many ways in which you could structure it.
For example, in my passives library I specify the base parts by <type>-<technology>-<package> so for surface mount ceramic parts, for the packages I would have SMT0201, SMT0402, SMT0603, etc and for the technologies I would have C0G/NP0, X5R, X7R, etc which would lead to a choice of:
CAP-C0G/NP0-SMT0201
CAP-C0G/NP0-SMT0402
.
.
CAP-X5R-SMT0201
.
.
CAP-X7R-SMT0201
.
.
etc...
Now, I provide attributes for specific part data such as the value, voltage, tolerance, rating, etc and have placeholders for these on the symbol so when I change the value and fill in the blank attributes these get annotated to the design. I also have links to datasheets and a ULP to provide quick access to the datasheets. You can do all sorts in this manner, you can add manufacturers and part numbers, you can use technologies to be more specific about the exact part, etc. The number ways of structuring the libraries and using them are many.
The key take away from this is, if the standard libraries which ship with EAGLE don't work for you then create your own how you like them. Pretty much everybody should be doing this anyway and should consider the standard libraries as only a "dirty resource" to find a starting point for building part. I refer to it as a "dirty resource" as it's just a massive collection of parts built up over 30+ years of EAGLE's existence and isn't to a consistent standard or in any way guaranteed to be accurate so even if you use it you need to thoroughly check the parts you use.
Best Regards,
Rachael
