Not too long ago, I wrote a post about one of my writing pet peeves: randomly redefining abbreviations. Another abbreviation annoyance is using them when you don't need to.
For example, I read a paper that abbreviated lead (Pb). I can’t fathom why the authors felt compelled to shorten a 4-letter word. Maybe it looked more scientific? It doesn't help that the chemical abbreviation doesn't match the English name. Yeah, I know that Pb is the chemical abbreviation for lead, but it still causes a little mental stop when you’re reading. And the paper was only about lead, and no other element, so it’s not like the authors were discussing a huge list of elements and wanted to keep the terms consistent.
We have enough abbreviations in scientific writing that are necessary. Let's not go cluttering up technical writing with extraneous ones.