BUR #61067 has been approved by @evazion.
rename 180_head_tilt -> 90_head_tilt
mass update id:4968238 -> 180_head_tilt
All of the posts currently under 180 head tilt are actually only 90 head tilt. Some of them are combined with 180 head turn but that still doesn't make the head tilt itself 180 degree. Those still have at most 90 degree head tilt.
post #4968238 is the only post I've seen so far that has actual 180 degree head tilt, which is basically the head being upside down.