Acronyms are words formed from the initial letters of other words and pronounced as they are spelled, not as separate letters. Examples include:
| acronym | full form |
| Aids | acquired immune deficiency syndrome |
| NATO | North Atlantic Treaty Organization |
| UNESCO | United Nations Educational, Scientific, and Cultural Organization |
| SIM (card) | subscriber identification module |
· Most acronyms can be written as capital letters or with only an initial capital letter.
· Some acronyms are so established that they are now 'normal' words, generally used without conscious awareness of their original full form. These words should be written in lower-case letters. Examples include:
| laser | light amplification by stimulated emission of radiation |
| radar | radio detection and ranging |
| quango | quasi-autonomous non-governmental organization |
| scuba | self-contained underwater breathing apparatus |
