LSB = Linux Standard Base.

From Wikipedia, "The Linux Standard Base (LSB) is a joint project by
several Linux distributions under the organizational structure of the
Linux Foundation to standardize the software system structure, including
the filesystem hierarchy, used with Linux operating system. The LSB is
based on the POSIX specification, the Single UNIX Specification, and
several other open standards, but extends them in certain areas"

I *think* that what it means is that it's a way to make all flavours of
Linux behave the same way under the hood so that developers don't have
to worry about the idiosyncrasies of each, but haven't really dug deep
enough into the subject to really be sure.