Scribal abbreviation by "contraction" and was mostly a Christian usage for sacred words, Nomina Sacra; non-Christian sigla usage usually limited the number of letters the abbreviation comprised and omitted no intermediate letter. One practice was rendering an overused, formulaic phrase only as a siglum: DM for "Dis Manibus" ("Dedicated to the Manes"); IHS from the first three letters of "ΙΗΣΟΥΣ"; and RIP for "requiescat in pace" ("Rest in Peace") because the long-form written usage of the abbreviated phrase, by itself, was rare. According to Trabe, these abbreviations are not really meant to lighten the burden of the scribe but rather to shroud
Phrase qualifies as a phrase, and the head-word gives its syntactic name, "subordinator", to the grammatical category of the entire phrase. But this phrase, "before that happened", is more commonly classified in other grammars, including traditional English grammars, as a subordinate clause (or dependent clause); and it is then labelled "not" as a phrase, but as a clause. Most theories of syntax view most phrases as having a head, but some non-headed phrases are acknowledged. A phrase lacking a head is known as exocentric, and phrases with heads are endocentric. Some modern theories of syntax introduce certain functional categories in which