entity set


Characters outside the SGML character set (CHARSET - usually 32-127) can be defined in subsiary files (e.g. iso-grk4.ent). They are refernced by general entities (e.g. alpha;) which are resolved (via the catalog mechanism) into data in these files. What happens then is postprocessor-dependent but could include instructions for conversion to TeX ('\aplha') which could then be typeset.