catalog
Synonym: Open Catalog
Synonym: SGML Open Catalog
A file which manages symbolic values of entities and FPIs. Although it takes a little while to get used to it, it can be very valuable and I recommend its use. It means, for example, that a DOCTYPE can reference an FPI rather than an actual file, making it easier to resolve this on a variety of systems. You may need to edit your catalog file. sgmls will support an arbitrary number of catalogs.