Page History

...

Abbreviations are shortened forms of words or phrases.  An acronym is a specific type of abbreviation formed from the initial letters of words and is sometimes pronounced as a word (e.g. AIDS for Acquired Immunodeficiency Syndrome; NICU for Neonatal Intensive Care Unit).  Neither abbreviation nor acronym is permitted in a fully specified name (FSN).

For example, 

• • Sperm is a shortened form of the word spermatozoa.  The proper term of spermatozoa should be used in the FSN, while sperm can be used as a synonym.

Abbreviations and acronyms are allowed in a preferred term or synonym when followed by the term expansion. If the abbreviation or acronym stands alone (meaning, no additional terms are included; the letters represent the entire meaning of the description without any other text), it is followed by a space, a hyphen, and another space, then the expanded term. The first word after the dash should be lower case as per usual capitalization rules.

...