If the "make tag" option is checked in the clearcase-ucm plugin settings of a job, and the clearcase hyperlink type tag is missing from the PVOB, an explanotory message is shown in the build log:

[CCUCM] Could not change tag in ClearCase. Contact ClearCase administrator to do this manually.
net.praqma.util.execute.AbnormalProcessTerminationException: cleartool: Error: hyperlink type "tag" not found in VOB "\Cool_PVOB" and no global type definition can be found.
cleartool: Error: Unable to create hyperlink "tag".
The Hyperlink type "tag" was not found.
Installation: "cleartool mkhltype -global -c "Hyperlink type for tagging entities" tag@\Cool_PVOB
Command was: cleartool mkhlink -ttext "tagtype=TestPosted&tagid=734&buildstatus=SUCCESS" tag baseline:Automade.8125@\Cool_PVOB
cleartool: Error: hyperlink type "tag" not found in VOB "\Cool_PVOB" and no global type definition can be found.
cleartool: Error: Unable to create hyperlink "tag".
[CCUCM] Post build steps done
Finished: SUCCESS

I think that the build should be failed instead, because I do not get the results I "ordered" in the job configuration. Or as a minimum, the build should become Unstable