This does not actually forward the report. This can be used to change an existing incorrect forwarded-to address, or to record a new one for a bug that wasn't previously noted as having been forwarded. If the bug was not recorded as having been forwarded then this will do nothing. Unlike most of the other bug-manipulation commands when used on one of a set of merged reports this will change the title of only the individual bug requested, and not all those with which it is merged. No notification is sent to the user who reported the bug.
Severities are critical, grave, serious, important, normal, minor, and wishlist.
For their meanings please consult the general developers' documentation for the bug system. Merges two or more bug reports. When reports are merged opening, closing, marking or unmarking as forwarded and reassigning any of the bugs to a new package will have an identical effect on all of the merged reports. If they don't start out in the same state you should use reassign, reopen and so forth to make sure that they are before using merge. If any of the bugs listed in a merge command is already merged with another bug then all the reports merged with any of the ones listed will all be merged together.