A mention of http://www.idicalif.com/proto.htm which has a much longer list would be useful, if (I don't know) Linux supports all of the entries in the web page list. Probably, /etc/protocols should say whether that is true, whether or not the web page's URL is given because many, like me, will find the web page.
Please note that the authoritative source for this sort of information is IANA: http://www.isi.edu/in-notes/iana/assignments/protocol-numbers