While some readers here are very familiar with the terminology of the field and would easily understand standard abbreviations, I am guessing that many readers coming here might benefit from inclusion of the expanded form.

The example that brought me to this question was the use of ISP in this answer. (Undo asked what ISP meant in a comment, so I would presumably not be the only one in the dark.)

Being a technical field with long terms, abbreviations are natural, and the goal of being friendly to professionals would tend to encourage their use.

Using the technical familiarity of the asker (estimated by the wording of the question itself) might be a useful guideline. If a question is very technical, those who can understand the question or its answers are more likely to be familiar with more field-specific terminology. If a question is relatively non-technical, the asker and many of those interested are less likely to be familiar with such.

The desired length and directness of posts does encourage a more compact (in reading length not necessarily character count) presentation and this medium is perhaps not as friendly to a glossary (though having such might be helpful) or depending on previous expansions of an abbreviation (answer order can change).

One possibility that comes to mind is to use "long term (LT)" format for terms that are less likely to be familiar and "LT (long term)" when the term is more likely to be discernible to the readers. The latter format might have most of the reading speed advantages of a bare abbreviation (the parenthetic expansion might be scanned over somewhat quickly) to those familiar with the term. (Very familiar an/or unambiguous abbreviations could stand without even parenthetical expansion.)

(Judging familiarity [or even discoverability] might be difficult, but I think some guidelines would be helpful.)

Note, I am not suggesting expansion of abbreviations that are proper names (whether of organizations or projects).

  • $\begingroup$ I try to explain used abbreviations and acronyms at least once, usually when I first mention them. I personally think such explanations (mostly just typing abbreviations as you'd pronounce them, and acronyms with their full name) make posts potentially less ambiguous. When I want to really emphasise the intended meaning, then I'd even stick to it a Wikipedia link as well. But some abbreviations will inevitably be too obvious to bother, e.g. NASA, which might have explanation in the selected tags anyway. If a request for clarification is posted in comments, then it's IMO best to edit it in. $\endgroup$
    – TildalWave
    Aug 21, 2013 at 23:43
  • $\begingroup$ I would support use of hyperlinks to wherever definitions can be found. $\endgroup$ Aug 22, 2013 at 4:38
  • $\begingroup$ @TildalWave "explain [...] at least once" plus a link is perfect. Do you mind turning this comment into an answer ;-) ? Actually, going by scientific standards, I would be careful with "obvious" abbreviations. I agree, everybody knows NASA, but for keeping things straight, I would actually encourage to explain/link all abbreviations ... $\endgroup$
    – s-m-e
    Aug 22, 2013 at 18:30
  • $\begingroup$ @DeerHunter Your edit of the linked answer was nice (particularly using subscripts for ISP), though I am curious why you did not make "RP-1" a link. $\endgroup$ Aug 23, 2013 at 13:01
  • $\begingroup$ @PaulA.Clayton - Nobody's perfect. $\endgroup$ Aug 23, 2013 at 14:53

2 Answers 2


I agree, acronyms and other abbreviations should be further explained at least once in posts they're used, regardless, if they're a question or an answer.

This has nothing to do with the depth of understanding of discussed topics by their readers. For example, IUA (The International Astronomical Union) abbreviation for the planet Mars is Ma. It just so happens, Ma is also an abbreviation for "millions of years ago" or Megaannum, and for Mach number, is a Vietnamese ethnic group, a language spoken in DRC Congo, and so on. And there are, of course, worse, even more ambiguous examples.

Additional bonus comes from SEO (Search Engine Optimization), making web search engines index our contents more precisely, and any hits we get due to more relevant indexing will bring us visitors that are more likely to stay, too.

Enforcing a single style might be a tough sell, though. To most of our contributors, I'd hope, Space Exploration isn't the primary target where they publish their work, and each would already have developped their own writing style, be it by mostly writing scientific journals, news articles, blog posts or other media where they might not be limited by text length and broadness of topics as much as they're dictated by our Q&A format. There's just too many possible annotation styles, and all serve the purpose of further explaining the meaning and/or avoiding ambiguity of used acronyms equally well.

Personally, I try to write contributions in ways I believe they will later be read by others, trying to preserve fluency. This might mean I'll even use different annotation styles throughout my posts (maybe also for variety, to avoid it being dull reading), but I try to explain the meaning of abbreviations at least once, and this might be done thusly;

  • Explain their meaning in written word, by writing it down "as read", not disturbing the reader's word flow too much, e.g.:

    NASA, the National Aeronautics and Space Administration agency of the United States government, will soon ...

  • Attach explanation in brackets, following the abbreviation used, e.g.:

    NASA (the United States National Aeronautics and Space Administration), will soon ...

  • Use marginal annotations by adding unique marks following used abbreviations, and explaining them in the footnote, captions to attached images, e.t.c., e.g.:

    * United States National Aeronautics and Space Administration

  • By using hyperlinks to simulate effects of semantic links similar to those used on our tags that have a tag wiki description (i.e. Wikipedia and a lot of other referenced web pages might use full names in their URLs, that display by simply hovering over a link in most browsers), or to also serve as an external reference, e.g.:

    ESA will soon ...

  • By combining multiple of described options to annotate, further explain and remove possible ambiguity of used abbreviations, or by explaining their intended meaning later on, either quoted in short excerpts, by re-emphasising it with additional explanation, or sometimes - simply answering a question that is using them, e.g.:

    Since ESA is the European Space Agency, ...

There are of course other methods, and each of us will have different style. I'm in no way trying to suggest how to achieve that, but I do agree that they are essential to better understanding of questions and their answers. Many different branches of science and technology will use possibly ambiguous abbreviations, if used in interdisciplinary topics stretching several of them, and their intended meaning might not be clear because of it.

TL;DR - If any such clarifications are required on already existing contributions, please go ahead and edit them, and they should be approved without further ado. Please do mind however, that questions and answers are automatically converted to community wiki, once they reach 10 revisions, as we don't want to rob their respective authors of reputation gained by upvoting and/or accepting them.


Could we possibly have a site glossary?

If the Stackexchange framework supports the process it may be a blog-post, or even simply a specific question with the title Glossary as is done here.

The answers could have relevant hyperlink, abbreviation, acronym, and description. A user could post an answer to add a term. The SO process would take care of the edit history, and site user sensibility would take care of the suitability of the term itself by way of upvote/downvote/flag for attention mechanism.

The glossary question itself could (assuming again the SE framework is so flexible) be made available on the 'Ask Question' page. This could allow any incoming user to refer/add to the glossary as necessary.

Of course it is moot how many people would choose to utilize/contribute tp such a facility. Those who do may well be the persons who even as yet provide references/quotes. For those who do not - a 'Glossary' question may perhaps provide a visible option to do the right thing.

  • $\begingroup$ This sounds to me more as a new proposal than an answer to the question (although I can see how it could help solve many problems, especially when using more exotic abbreviations). I suggest you post a new proposal / question, and we see what the community thinks of it. We certainly have the means to achieve that with the tools available, for example with a simple "question" with a single community wiki answer that anyone can edit, but probably best kept here in meta, not to constantly pop on top of active questions on the main site. Anyway, post a new meta question. ;) $\endgroup$
    – TildalWave
    Sep 6, 2013 at 2:51

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