What is Standard Generalized Markup Language?
Readers familiar with USMARC or MARC in any of its varieties will find that it both helps and hinders acquiring an understanding of Standard Generalized Markup Language (SGML). Knowledge of MARC helps because MARC prescribes content designation and not presentation formatting, indexing, or any other use of the content itself. MARC records can be used to print catalog cards or for online screen displays. Content designation is very much what SGML intends. Thus both MARC and SGML are about what is in documents, and not what you do with that content. MARC hinders an understanding of SGML in that MARC is dedicated to one kind of document, the bibliographic record–efforts to expand it to other categories notwithstanding. From this it follows that MARC software is dedicated to one document type, the MARC record. SGML differs markedly (no pun intended) from MARC in this regard. While Standard Generalized Markup Language is both standard (ISO 8879) and generalized, it does not provide an off
