As a programmer I use the word Authentication and the word Authorisation in my code.

I'd like to find nice abbreviations or alternative words for each of them that

  • are not ambiguous and
  • has reasonably large 'psychological distance' between. i.e. they don't look too similar

i.e 'Auth' is not OK because it is ambiguous.

At the moment I have just removed some letters

  • Authtictn
  • Authristn

Any suggestions?

Update: Since this question is now under threat I have moved it's gist to:


  • 4
    Yeah, the problem is that "authtictn" and "authristn" have the same length, differ by just 2 letters, and have 7 letters in common. In other words, that approach has actually removed some of the differences, but left most of the similarities intact. You should probably try to do the opposite thing, by emphasizing the "entic" vs the "oris".
    – RegDwigнt
    Sep 10, 2010 at 21:37
  • 5
    At risk of sounding arrogant, I suggest you don't use abbreviations. Don't be lazy and type the complete words. See McConnell's "Code Complete" for the rationale.
    – CesarGon
    Jan 15, 2011 at 18:58
  • I agree with the principal of declarative naming, but in practice - I develop on a windows PC and use subversion. This means that I am constrained by a maximum file path length. Which means I am forced to shorten words. In an ideal World, Adobe would offer their Creative Suite to Linux users (pending soon I believe). Or some bright spark would set up up an OS version of it (like Open Office Suite). stackoverflow.com/questions/3282303/…
    – JWEnglish
    Jan 15, 2011 at 21:40
  • 4
    Off topic. This is a kind of "name the variable" question. This type of question is really quite unrelated to the purpose of the site.
    – MetaEd
    Feb 7, 2014 at 0:15
  • 2
    @MετάEd I don't think you have spent as long thinking about this question as I did before asking it. It is not a 'typical name the variable question'. In the three years that it has been here, this question has helped hundreds of people solve a very tricky English language problem.
    – JWEnglish
    Feb 7, 2014 at 18:18

7 Answers 7


I've worked with IETF people and developers who spend a lot of time on Apache, who tend to use:

AuthN - Authentication
AuthZ - Authorization

You'll find these abbreviations in a lot of IETF technical documents.
Yes, I know British spelling prefers s over z (authorisation).

  • Thanks for this. If the convention exists already, then it makes sense to follow it.
    – JWEnglish
    Sep 13, 2010 at 14:25
  • 1
    "Authorization" is an acceptable spelling in British English, and is actually the preferred spelling in the Oxford English Dictionary.
    – tobyink
    Feb 26, 2014 at 16:50
  • The convention is interesting but it's still a single-letter difference.
    – Ekevoo
    Oct 1, 2015 at 18:32
  • ...and that single-letter difference is only rotated 😊 But nobody confuses Nap and Zap... AuthN/AuthZ is fine, even the pronunciation gives clear hints about the original.
    – Hugues M.
    Sep 6, 2017 at 8:17

You could think of replacing the word 'authentication' with 'identification', since in this context, I think they are probably equivalent.

You could then substitute 'authorization' with 'permission'.

Then, abbreviate as 'ident' and 'perm'.

  • The only concern is that I might still end up wondering if Auth = Authentication or Authorisation. But, I really like this idea. Its got legs. If i could find an alternative for Auth as well , then it will be solved.
    – JWEnglish
    Sep 10, 2010 at 20:54
  • Good point. I edited my answer with a new suggestion.
    – pkaeding
    Sep 10, 2010 at 23:18
  • 'credentials' might work as a synonym, too.
    – kajaco
    Sep 11, 2010 at 17:01
  • Not exactly. Authentication is the process of evaluating credentials to see if they are acceptable. May 29, 2012 at 4:13

I suppose you could take the approach taken when abbreviating 'internationalization' as 'i18n' (and 'localization' as 'l10n':

  • 'authentication' => 'a12n'
  • 'authorization' = > 'a11n'

The idea is to keep the first and last letters of the word, and replace all of the interior letters with a number representing the count of the letters removed.

Of course, looking at 'a12n' and 'a11n', you may not know the meaning right away, so this is probably not the best solution.

  • Thanks for the suggestion. But as you say it might be difficult to remember that 12 = authentication and 11 = authorization
    – JWEnglish
    Sep 10, 2010 at 20:52
  • And only 1 character is different between the two, and a middle one at that.
    – kajaco
    Sep 11, 2010 at 17:02
  • Yeah, this isn't the best approach, I am sure. I mostly suggested it because I thought the internationalization/localization abbreviations were clever, and I am curious if this scheme can/will be used elsewhere.
    – pkaeding
    Sep 11, 2010 at 22:20

authent. and authoris.? I would say that your current versions are fairly difficult to read, and also not particularly easy to tell apart from one another at a glance.


I would chose a synonym

  • authenticate synonyms: attest, authenticate, avouch, testify (to), vouch (for), witness
  • authorization synonyms: allowance, authorization, clearance, concurrence, consent, granting, green light, leave, license (or licence), sanction, sufferance, warrant

(As a non-native speaker) I would chose attest and grant.



Why not just: - Autho - Authe


What about this:


Auth'tion? We were tought to put aphostrophoes somewhere to shorten a word.

  • 1
    Putting apostrophes into words still follows a general principle. You shouldn't just stick them in wherever. Whacking the 'r' from both words really mucks with the pronunciation; I would try something more like "Au'rization" or "Au'ri'tion". But really, this is so non-standard as to be moot.
    – MrHen
    Apr 25, 2011 at 15:25

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