Abbreviations, initialisms, and acronyms are likely to be ambiguous needing disambiguation. Thus abbr. should usually be expanded (see Naming conventions (acronyms) ) beforehand.

For two- and three-letter combinations, there is generally a list detailing a few or many possible uses.

Sample Wiki markup for abbreviations

:''Alternate use: [[ISO country code]] for [[Slovenia]]''

:''Alternate uses: see [[SI (disambiguation)]]''

'''AU''' or '''Au''' may stand for:

*[[Australia]] ([[ISO country code]])
*[[Astronomical Unit]] ('''AU''')
*atomic units ('''au''')
*Au, a place name in:
**Austria:
*gold ('''Au'''), [[symbol for the chemical element]]

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''This page expands and [[Ireland Information Guide:Disambiguation|disambiguates]]
a two- or [[TLA|three-letter]]-abbreviation. If you followed 
a link here, you might want to go back and fix that link to point 
to the appropriate specific page.''

• If there is an article that is named that way (e.g. SI, Ur, pH), the page should be used for the article at one of these pages, rather than the page with the abbreviations.
• Abbreviations pages replace disambiguation pages (see Ireland Information Guide:Disambiguation).
• Usually, there should be just one page for all cases (upper- or lower-case), e.g. MB for MB, mB, mb, Mb.
• If the case of the abbreviation is important (e.g. for SI Units, symbols for chemical elements), the exact one should be noted. In the sample above: atomic units (au), gold (Au), .
• For two-letter combinations, If there is no article, the page is usually placed at the uppercase version (BA), the lowercase (Ba) redirecting there.
• Abbreviations with dots, usually redirect to the "undotted" version: DC., D.C, D.C., D. C. could redirect to DC.

2-3 letter combinations

• 2-letter
  • List of all two-letter combinations
• 3-letter
  • see TLA
  • TLAs from AAA to DZZ
  • TLAs from EAA to HZZ
  • TLAs from IAA to LZZ
  • TLAs from MAA to PZZ
  • TLAs from QAA to TZZ
  • TLAs from UAA to XZZ
  • TLAs from YAA to ZZZ

Abbreviations

The following group undisambiguated abbreviations in the Ireland Information Guide namespace. It can be helpful to make sure that the abbreviation links to the abbreviated article title (if such an article exists).

• Organizations with .INT domain names
• Undisambiguated_abbreviations/CIA_World_Factbook
• Undisambiguated_abbreviations/Country_codes
• Undisambiguated_abbreviations/Currency codes
• Undisambiguated_abbreviations/Elements
• Undisambiguated_abbreviations/units of measurement
• Undisambiguated_abbreviations/State codes
• Undisambiguated abbreviations/file extensions

Miscellaneous information

• List of acronyms
• List of initialisms
• List of computing and IT abbreviations
• List of government and military acronyms
• User:Egil/Sandbox