---
title: "Abbreviations and acronyms"
source: 18F Guides
source_url: https://github.com/18F/guides
licence: CC0-1.0
domain: engineering
subdomain: 18f-guides
date_added: 2026-04-25
---

Abbreviations are any shortened or contracted word or phrase. For example, writing *St.* instead of *Street*, or *Rx* for *prescription*, or *DC* for *District of Columbia*.

Acronyms are a *type* of abbreviation. They shorten phrases in a specific way— using parts of the initial word or phrase (usually letters) to form an abbreviation. For example, *DIY* or *ASAP*.

In the most technical sense, there is a difference between acronyms (abbreviations pronounced as words, like *NASA*) and initialisms (abbreviations pronounced as letters, like *FBI*). For simplicity, our content guide refers to both as acronyms. The readability issues that acronyms and initialisms create tend to be similar, and “acronym” is the more common term.

**Acronyms often confuse readers. Avoid them whenever possible.**

If an acronym is necessary for future reference, spell the full word and follow with the acronym in parentheses on the first reference. For example, *The General Services Administration (GSA)*.

Some acronyms are more recognizable than their full spellings. For example, *NASA*, *NAACP*, *FBI*. In such instances, the acronym is always acceptable, at the writer’s discretion.

At the writer’s discretion, refer to organizations on second reference with a shortened name instead of an acronym. For example, use *Labor* in place of *Department of Labor*, rather than *DOL.*
