Can there be a URI for the concepts "I", "you", "this", "it", "here", "there", "now", etc.?

Are the following URI allowable according to web and semantic 
web standards? Are they ambiguous? Are they useful? In each case, 
the referent would depend on the context of the use[1] of the URI.

http://kashori.com/ontology/indexicals.owl#I
http://kashori.com/ontology/indexicals.owl#you
http://kashori.com/ontology/indexicals.owl#this
http://kashori.com/ontology/indexicals.owl#it
http://kashori.com/ontology/indexicals.owl#here
http://kashori.com/ontology/indexicals.owl#there
http://kashori.com/ontology/indexicals.owl#now

Therefore they would only be of use if they could be embedded in a 
structure that specified a context. I would like to find (or define) an 
ontology that specified this type structure. 

[1] http://www.indiana.edu/~hlw/Meaning/deixis.html

cheers,
John Black
www.kashori.com