Rules And Conventions That One Needs To Know Or Follow In Order To Validly Record Information, Or Interpret Previously Recorded Information, For A Specific Purpose. Thus A Syntax Is Sentence Structure And Language Rules—Grammar. Such Rules And Conventions May Be Either Explicit Or Implicit. In X12 Transactions The Data-Element Separators, Subelement Separators, Segment Terminators, Segment Identifiers, Loops, Loop Identifiers (When Present), Repetition Factors, And So On Are All Aspects Of The X12 Syntax. When Explicit, Such Syntactical Elements Tend To Be The Structural, Or Format-Related, Data Elements That Are Not Required When A Direct Data Entry Architecture Is Used. Ultimately, Though, There Is Not A Perfectly Clear Division Between The Syntactical Elements And The Business Data Content.