Source: https://developers.google.com/style/abbreviations\n\n# Abbreviations



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      Save and categorize content based on your preferences.\n\n- Home\n- Products\n- Style\n\n\n## Page Summary\n\n- Abbreviations encompass acronyms, initialisms, shortened words, and contractions, and are used to save time and space.\n- When introducing an abbreviation, spell it out on first reference, italicizing both the full term and the abbreviation, then use the abbreviation alone in subsequent mentions.\n- Avoid using abbreviations that are unfamiliar to your audience, overly specialized, or internet slang, opting for clear and concise language.\n- Generally, omit periods in acronyms and initialisms, but include them with shortened words (except for date/time) and country/state abbreviations.\n- Treat abbreviations as regular words for pluralization, adding 'es' to those ending in 's', 'sh', 'ch', or 'x', and refrain from using them as verbs.\n\nAbbreviations encompass acronyms, initialisms, shortened words, and contractions, and are used to save time and space.\n\nWhen introducing an abbreviation, spell it out on first reference, italicizing both the full term and the abbreviation, then use the abbreviation alone in subsequent mentions.\n\nAvoid using abbreviations that are unfamiliar to your audience, overly specialized, or internet slang, opting for clear and concise language.\n\nGenerally, omit periods in acronyms and initialisms, but include them with shortened words (except for date/time) and country/state abbreviations.\n\nTreat abbreviations as regular words for pluralization, adding 'es' to those ending in 's', 'sh', 'ch', or 'x', and refrain from using them as verbs.\n\nAbbreviations include acronyms, initialisms, shortened words, and
contractions.\n\nIn most contexts, the technical distinction between acronyms and initialisms
isn't relevant; it's fine to use the word acronym to refer to both.\n\n- An acronym is formed from the first letters of words in a phrase, but is
pronounced as if it were a word itself:

NATO for North Atlantic Treaty Organization
scuba for self-contained underwater breathing
apparatus\n- NATO for North Atlantic Treaty Organization\n- scuba for self-contained underwater breathing
apparatus\n- An initialism is also formed from the first letters of words in a phrase,
but each letter is pronounced separately:

CIA for Central Intelligence Agency
FYI for For Your Information
PR for Public Relations\n- CIA for Central Intelligence Agency\n- FYI for For Your Information\n- PR for Public Relations\n- A shortened word is just part of a word or phrase, sometimes with a
period at the end:

Dr. for doctor
etc. for et cetera
min for minutes
CA for California\n- Dr. for doctor\n- etc. for et cetera\n- min for minutes\n- CA for California\n- Contractions are discussed in a
separate page of this style guide.\n\n- NATO for North Atlantic Treaty Organization\n- scuba for self-contained underwater breathing
apparatus\n\n- CIA for Central Intelligence Agency\n- FYI for For Your Information\n- PR for Public Relations\n\n- Dr. for doctor\n- etc. for et cetera\n- min for minutes\n- CA for California\n\n\n## Long and short versions of a word\n\nSome words have a long version and a short version—for example:\n\n- application and app\n- demonstration and demo\n- synchronize and sync\n\nThe short versions of the words are not abbreviations, and
if you use them, you don't need to put a period after them.\n\nIf you're not sure whether a word is an abbreviation or just a short version
of a longer word, look in our list of resources.
If that doesn't settle the issue, use the speaking test: if you speak the short
version as a word (This is a demo version of the product), you can usually
treat it as a word and not an abbreviation.\n\n\n## When to use abbreviations\n\nAbbreviations are intended to save the writer and the reader time. If the reader has to
think about an abbreviation, it can slow down their reading comprehension.\n\n\n### General dos and don'ts\n\n- Use standard acronyms and initialisms that will save the reader time.\n- Spell out abbreviations on first reference. For more information,
    see When to spell out a term.\n- Avoid using abbreviations for terms that aren't related to the main topic of the document.\n- Be wary of using specialized abbreviations that your readers might not understand. For more information about when to use such language, see Jargon.\n\nIn the following examples, the main topic of the document is the internet of things, so low Earth orbit should not be abbreviated.\n\nRecommended: The internet of things (IoT)
    service can even be used for connecting to sensors in low Earth orbit.\n\nNot recommended: The IoT (internet of things)
      service can even be used for connecting to sensors in LEO (low Earth orbit).\n\n\n## When to spell out a term\n\nIn general, when an abbreviation is likely to be unfamiliar to the audience, spell it out upon
  first mention and include the abbreviation in parentheses immediately following.\n\nRecommended:  Border Gateway Protocol (BGP)\n\nFor all
subsequent mentions of the abbreviation, use the abbreviation by itself. If you use an abbreviation
only once, include it only if you think the abbreviation is as commonly used as the spelled-out
term. Otherwise, don't include the abbreviation.\n\nIf the first mention of
a term occurs in a heading or title, you can use the abbreviation and
then spell out the abbreviation in the first paragraph that follows the heading or title.\n\nWhen deciding to spell out a term, consider your audience. If your document is going to be
translated, spelling out a term can provide important context for both human and machine translation.
It can also be helpful for readers who aren't as familiar with English. If the
majority of your audience is likely to recognize and understand the term, then you don't need to
spell it out. For example, if you're writing documentation for developers that references an API,
you don't need to spell out application programming interface. However, if you're explaining
the general concept of an API to someone with no programming experience, spelling out the
abbreviation can be helpful.\n\nIn some cases, spelling out a term doesn't help the reader
understand the term. For example, writing out portable document format doesn't help the
reader understand what a PDF document is. In those cases, don't spell out the term.\n\nThe following abbreviations rarely need to be spelled out:\n\n- AI\n- API\n- DVD\n- File formats such as PDF or XML\n- HTML\n- PC\n- RAM\n- REST\n- Units of measurement such as
      MB, MiB, GB, or GiB\n- URL\n- USB\n\n\n### Format abbreviation introductions\n\nWhen you spell out a term and include its abbreviation in parentheses, do the following:\n\n- Italicize both the spelled-out term and its abbreviation.\n- Capitalize the spelled-out version of the abbreviation only if the long form is a proper noun or is conventionally capitalized.\n- Include the abbreviation in link text.\n\nIn the following examples, the only difference is the italicization of BGP:\n\nRecommended: Establish Border Gateway Protocol (BGP) sessions using a router on the peer network.\n\nNot recommended: Establish Border Gateway Protocol (BGP) sessions using a router on the peer network.\n\nThat is, don't capitalize the term only because the abbreviation includes capital letters.\n\nRecommended: data manipulation language (DML)\n\nNot recommended: Data Manipulation Language (DML)\n\n\n## Abbreviations not to use\n\nDon't use i.e. or e.g.; instead, use that is or
for example, respectively. For more information, see
e.g. and
i.e.\n\nIt's okay to use etc. in
some circumstances, but it's best to use different phrasing in most lists.
For more information, see
Comma-separated lists.\n\nDon't use internet slang abbreviations such as
tl;dr,
ymmv,
RTFM, or others. Write out what you
mean in a non-figurative way.\n\nUse the most common form of a word. If the spelled-out word is common
and easily understandable, use that rather than abbreviating. For example, write
approximately instead of approx.\n\nSpell out shortened words or common symbols that are substitutions for words.\n\nRecommended: Updating the software made
throughput 10 times faster.\n\nNot recommended: Updating the software made
throughput 10x faster.\n\n\n## Periods with abbreviations\n\nFollow these guidelines:\n\n- Don't use periods with acronyms or initialisms.\n- Put a period at the end of a shortened word, except for
date and time abbreviations.\n- If you write or say an abbreviation as a word (for example, app or
sync), don't put a period after it.\n- Don't use a period with an abbreviation for the name of a country, US
state, or the District of Columbia (DC).\n\n\n## Plural abbreviations\n\nFor guidance about how to make abbreviations plural, see Pluralization.\n\n\n## Abbreviations as verbs\n\nDon't use acronyms, initialisms, or shortened words as verbs.\n\nRecommended: Use SSH to
log in to your remote shell.\n\nNot recommended: Then ssh
into your remote shell.\n\n\n## Indefinite articles before abbreviations\n\nWhether to use a or an before a term depends on the pronunciation of the term:
  use a before any consonant sound and an before any vowel sound. Pronunciation of
  abbreviations can vary, so in general, base your decision on the pronunciation that's most common
  for your audience.\n\nIn particular, our word list includes preferences for
  "a SQL", "a FHIR",
  and "an SAP".\n\nFor more information about articles, see Articles.\n