An abbreviation is a shortened graphical representation of a word or group of words through the removal of some letters or syllables. For example: art. (per item), chap. (per chapter), FF. AA. (Armed forces).
Most abbreviations end with a dot, although there are cases where slashes or flown numbers are used. For example: a/c (for on account), 3rd (for third).
To create an abbreviation, there are two procedures.
Any word can be abbreviated, but there is a distinction between the abbreviations accepted by a small group of people or those accepted in the general use of the language:
It is worth mentioning that, in general, abbreviations are written with upper or lower case depending on the word or words being abbreviated. For example: am (ante merídiem), d. C. (after Christ), Bs. As. (Buenos Aires). However, this is a rule that has exceptions, as is the case with treatment formulas. For example: Ud. (you), Dr. (doctor), Mrs. (ma'am).