4.2. Configuration needed

The identifier systems used by SGML and by some tools are based on catalogues that perform the translation of these identifiers to files that hold the necessary definitions.

The section on tailoring a catalogue (see Section 4.3) will give more details about these files.

For tools to be able to find the necessary catalogue(s), the environment variable SGML_CATALOG_FILES should be set, as shown in the following example:

$ export SGML_CATALOG_FILES="/usr/lib/sgml/catalog"

This is the only necessary additional configuration for DocBook tools and the like to work correctly on your platform.