described as ‘MSP.ROLE’, where <cite>MSP</cite> represents the required MSP
ID (the organization),  and <cite>ROLE</cite> represents one of the four accepted roles:
Member, Admin, Client, and Peer. A role is associated to an identity when a user
enrolls with a CA. You can customize the list of roles available on your Fabric
CA.</p>
<p>Some examples of valid principals are:
* ‘Org0.Admin’: an administrator of the Org0 MSP
* ‘Org1.Member’: a member of the Org1 MSP
* ‘Org1.Client’: a client of 