A syllabic abbreviation is an abbreviation formed from (usually) initial syllables of several words, such as Interpol = International + police.
Syllabic abbreviations are usually written using lower case, sometimes starting with a capital letter, and are always pronounced as words rather than letter by letter.
Syllabic abbreviations should be distinguished from portmanteaus.
Usage in different languages
Syllabic abbreviations are not widely used in English or French.
On the other hand, they prevailed in Germany under the Nazis and in the Soviet Union. For example, Gestapo stands for Geheime Staats-Polizei, or "secret state police". Similarly, Comintern stands for the Communist International. This has caused syllabic abbreviations to have negative connotation, notwithstanding that such abbreviations were used in Germany even before the Nazis came to power, e.g., Schupo for Schutzpolizei.
East Asian languages whose writing uses Chinese ideograms instead of an alphabet form abbreviations similarly by using key characters from a phrase. For example, in Japanese the term for the United Nations, kokusai rengō (国際連合) is often abbreviated to kokuren (国連). Such abbreviations are called ryakugo (略語) in Japanese. The classic example, of course, is shogun.
Usage in organisations
Syllabic abbreviations are prefered by the US Navy as it increases readability amidst the large number of initialisms that would otherwise have to fit into the same acronyms. Hence DESRON 6 is used (in the full capital form) to mean "Destroyer Squadron 6," while COMNAVFORLANT would be "Commander, Naval Force (in the) Atlantic."