The standard that succeeded MIL-STD-490 at Revision D. It was upgraded to attempt addressing development specifications after MIL-STD-490 was canceled. It never really did the job.
Standards for specification practices headed downhill fast with (and following)MIL-STD-961. To be honest, they got so bad that I quit paying attention around the turn of the century. Maybe they got better since then, but my occasional forays into the field support no such conclusion. I give up!