5.1.1 is a maintenance release.  That means that what it has are bug fixes.
There is occasionally new function "slipped in" because development has promised
something to a customer and there is no other way to ship it, but for the most
part (99%) it is all fixes.

The third digit in IBM/Tivoli products always denotes this.   The nomenclature
is "version.release.mod_level".
Different mod levels are achieved through some kind of patch mechanism, new
releases may require migration, and new versions always do.  New mod levels are
available at no cost, as they are just a way to package fixes.    Soft copy doc
amy be changed at the mod level or release level, but hard copy doc never is.
It is published only once per version.  If soft copy is updated at the release
or mod level, then it is shipped as part of the package.

So the requirements and the doc for 5.1.1 are the same as for 5.1

If a customer has a problem on 5.1, he will be asked to put on 5.1.1 before
Support pursues it.

James Shanks
Tivoli (NetView for UNIX) L3 Support