Here's some helpful info they provided on one of our tickets to get you started as not sure any of this is truly documented anywhere in Atlas/API Docs:
V1 check field: https://devdocportal.khoros.com/t5/Community-API-v1-Reference/bd-p/restv1docs?section=commv1&leaf-id=Board.settings#Board.settings
V1 set field: same as above but add \"/set?value=desired_value_here\"
V2 check field: https://developer.khoros.com/khoroscommunitydevdocs/reference/update-a-board
V2: set field: \"/set?value=desired_value_here\"
A quick example would be https://community.stage.upwork.com/restapi/vc/boards/id/Agencies/settings/name/custom.event_language to check the field and https://community.stage.upwork.com/restapi/vc/boards/id/Agencies/settings/name/custom.event_language/set?value=desired_value_here to set the 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Comments}}","title@board:IDEA":"{count, plural, one{# Comment} other{# Comments}}","title@board:OCCASION":"{count, plural, one{# Comment} other{# Comments}}","noRepliesTitle":"No Replies","noRepliesTitle@board:BLOG":"No Comments","noRepliesTitle@board:TKB":"No Comments","noRepliesTitle@board:IDEA":"No Comments","noRepliesTitle@board:OCCASION":"No Comments","noRepliesDescription":"Be the first to reply","noRepliesDescription@board:BLOG":"Be the first to comment","noRepliesDescription@board:TKB":"Be the first to comment","noRepliesDescription@board:IDEA":"Be the first to comment","noRepliesDescription@board:OCCASION":"Be the first to comment","messageReadOnlyAlert:BLOG":"Comments have been turned off for this post","messageReadOnlyAlert:TKB":"Comments have been turned off for this article","messageReadOnlyAlert:IDEA":"Comments have been turned off for this idea","messageReadOnlyAlert:FORUM":"Replies have been turned off for this discussion","messageReadOnlyAlert:OCCASION":"Comments have 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