An acronym is a term formed by each of the initial letters of an expression made up of several words. The word sigla, as such, comes from the Late Latin sigla, meaning 'ciphers' or 'abbreviations'.
It is also known by the name of acronym to each of the letters that make up the acronym in question. Thus, for example, OAS stands for Organization of American States, in the same way that the letters o, e and a are.
The acronyms are used to refer in an abbreviated way to organizations, institutions, companies, associations, objects, devices, technologies, systems, methods, etc., whose names are made up of several terms.
In the formation of acronyms not all the words are taken, but only the nouns, verbs and adjectives, while the articles, determiners, prepositions and conjunctions are not taken into account. For example: United Nations Organization returns UN.
Acronyms should never be accented, neither when one of the letters it takes was originally accented, nor when current spelling conventions so suppose. For example: NATO, for North Atlantic Treaty Organization, or CPI, for consumer price index.
Acronyms that abbreviate two plural words must be written with double initials: USA, for the United States, or HR, for human resources.
The acronyms, as a general rule, must be written in capital letters (OAS, VAT, FIFA), except in cases where, as a consequence of their use, they are considered as a common name by dictionaries, as in the case of UFO , flying object. unidentified, icu, intensive care unit. _ _
Acronyms should not be separated by periods or spaces. For example: ICU, intensive care unit, USA, United States.
Acronyms do not have graphic plurals. To mark a plural, it must be accompanied by the acronym of an article, a demonstrative or an adjective. For example: " the NGOs...", "these NGOs...", " some important NGOs..." It is incorrect to indicate the plural in writing by adding an -s at the end: ONG's, ONGs.
Acronyms adopt the gender of the main word of the expression. For example, in the UN, from United Nations Organization, the main term is "organization", which is feminine, so we will speak of the UN.
Acronyms can also be formed by combining numbers and letters. For example: G8, from the group of eight, or 11-S, from September 11.
Acronyms can be pronounced by spelling or by syllabic pronunciation:
By spelling, the acronym is referred to by articulating the name of each of the letters of which it is composed, such as ONG, pronounced “o-ene-ge”.
In the syllabic pronunciation, the acronym is read as a word, however, for this the composition of the acronym must allow its pronunciation, for example, NATO can be pronounced "nato".
It happens that when an acronym is so frequent that it can be considered fully incorporated into the vocabulary of the language, then it becomes a common word, and, consequently, it is governed by the current orthographic rules of the language, this means that it adopts the conventions for the formation of plurals (UFOs), for their accentuation (laser, plane), and that can be written in lowercase, except when referring to a proper noun, in which case the initial will be capitalized as long as it is formed by more of four letters. For example: Unesco, from the United Nations Educational, Scientific and Cultural Organization.