Update edu.adoc

id/Internet2/edu.adoc

@@ -13,7 +13,7 @@
 
 
 * Construct a Trust and Identity registry tree, top level of which should be 'https://id.internet2.edu/ti'.  
-* Next path element under /ti is selected from the extensible controlled vocabulary:  oid', 'urn', 'url', 'namespace', 'spec', 'schema', 'fed'
+* Next path element under /ti is selected from the extensible controlled vocabulary:  oid', 'urn', 'url', 'namespace', 'spec', 'schema', 'fed?'
 ** E.g.'https://id.internet2.edu/ti/urn'
 * Final fragment (after #) is an identifier of the type labeled by the parent node and must be unique within the scope of that parent
 ** E.g. https://id.internet2.edu/ti/urn#mace:osu.edu