OWL-S 1.1 has_process parameter

Hi!

Being rather new to OWL and OWL-S I noticed that the has_process 
parameter is the only of these "has" parameter written this way 
(underscore between both words and the entire name in lower case) while 
all other parameters  (hasInput etc) use a different way.

It caught me by surprise so I wondered if this intentional or just an 
accident?

Regards,

Ben Fries