LSE-77 was last baselined in October 2013 (Docushare v6), and there is an unapproved later version of it (Docushare v7) from July 2014.
There appears to be no outstanding LCR against LSE-77 to get that later version adopted.
There was a recent change request (LCR-384, Base Facility Data Center Requirements Under Change Control) whose purpose was to place a new document, LSE-239, Base Facility Data Center Design Requirements, under change control. This document amounts to the rollup by T&S of all the requirements from the LSST subsystems for data center space at the Base Facility.
In the process of developing that LCR, it was discussed that it should be synced with an update to LSE-77. At this point, LCR-384 has passed CCB review and is in "Approval Pending" state. It would be timely to reassess the status of LSE-77 - whether it is still useful at all, whether it should be updated with the final DM input that went into LSE-239, etc. - and what work may still remain to be on it to bring the interface to the completion of Phase 3.