Best Practices for Establishing Namespace Name

We are trying to decide on a namespace URI for an XML schema under development by a standards committee in the aerospace industry.
 
Are there best practices that we could follow?  For example, the choice between URL and URN, case sensitivity, unique components in the name, and incorporation of RDDL, etc.
 
Also, are there good example namespace names already established by standards committees such as those in OASIS?
 
 
Thanks,



Scott Tsao 曹壽國
Associate Technical Fellow 
The Boeing Company