It is often convenient to use the hlink command as part of software-maintenance procedures, such as in makefiles, since this allows your documentation set to be re-linked automatically whenever software is installed or de-installed. However, in a large software installation this can take some time. Rather than re-linking after each item of software is changed, it can sometimes be more efficient to wait until a sequence of changes has been completed. A grand re-link of the entire documentation set can then be performed.
To permit this, you can set the HTX_NOLINK environment variable
(to any value). While this variable is set, the hlink command
will cease to function normally. Instead. it will simply produce a
message saying that hypertext linking has been suppressed. You can
then perform your software updates without waiting for re-linking to
occur. When you have finished, you can un-set the HTX_NOLINK
environment variable and use hlink to bring the cross-references
in the associated documentation up to date.
HTX Hypertext Cross-Reference Utilities