The html documentation is generated using a2x which calls docbook tools to do the work. The generate.consistent.ids parameter ensures that when the docbook stylesheet assigns an id value to an output element it is consistent as long as the document structure has not changed. Having consistent html files reduces frivolous changes between builds. Distributions can more easily deploy multiple architecture builds and compare changes between package versions. End-users avoid needless changes in files deployed or backed up. The generate.consistent.ids parameter was added in docbook-xsl-1.77.0. Older versions gracefully ignore the parameter, so we can pass the parameter unconditionally. Most distributions contain docbook-xsl newer than 1.77.0. This includes Fedora, Debian, Ubuntu, and RHEL/CentOS 7. RHEL/CentOS 6 and Debian Wheezy (old stable) ship with an older version, unsurprisingly. Signed-off-by: Todd Zullinger <[email protected]>