BUR #55143 has been approved by @nonamethanks.
create implication side_sitting_split -> sitting_split
create implication front_sitting_split -> sitting_split
remove alias middle_split -> sitting_split
create alias middle_split -> side_sitting_split
create alias forward_sitting_split -> front_sitting_split
The previous version was abandoned with no votes hence me retracting it, so I renew the BUR rather than necroing the forum.