Short names can be more readable than long ones.

Abbreviations shorten names, and thus can help readability.

Too-short names, however, can be utterly confusing. pbya is not a clear name (it turned out to mean post by author).

The following is a list of abbreviations I believe strike a good balance between brevity and readability. They should not usually be used by themselves, but they are good building blocks when naming things.

alg

"algorithm" - When choosing algorithms dynamically, this can come in handy.

btn

"button" - handy in GUI programming.

cls

"class" - For when you have a reference to an actual class, as opposed to an instance of a class. Used frequently in Python.

cmd

"command" - useful when writing command-line programs.

cur

"current" - useful when dealing with ordered data structures. See also prev and next.

dir

"directory" - useful when doing filesystem manipulation.

msg

"message" - handy when writing message display or processing code.

opt

"option" - useful when writing command-line programs, or dealing with user preferences. Sometimes used as a top-level dir in a *nix-ish directory tree.

prev

"previous" - pairs well with 'next' when dealing with ordered data structures.

para

"paragraph" - useful when formatting text.

pos

"position" - index in an ordered data structure. Clearer than the traditional 'idx'. Often a good suffix.