About: http://webisa.webdatacommons.org/207598306

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Examples of things which are essential include Shabbat and Yom Tov according to one opinion in Tosfot (though we rule it is a doubt and one should pray Tashlumin as a Nedava if possible).
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com