The topic which I am going to talk about is one of the least discussed topics in the forum 
But, I am sure it would be a great tip in organizing and maintaining roles in much ordered, definable and meaningful manner.
Going back to the title of the blog “30 Characters”. I wanted to highlight on the fact that PFCG role naming convention is limited to 30 characters. So, all your creativity of putting across a meaningful name to the role will be limited to 30 characters.
Take for a example this PFCG Role - Y: SLS_CUS_SER_EMEA
Some of the points to be noted while making a role name
1. All the customized or the nonstandard roles should start with Y or Z, that is pretty much obvious you cannot use SAP standard roles 
2. Next, you can use a (:) as a divider between Y/Z and the naming. It aids readability.
3. SLS: Represent a department name or module
4. _ aids as a separator and helps in readability
5. EMEA: Represents the region
6. There are many other tip which might be of help like
- Start all the composite role with X and single roles with Y
i. Single Role - Y: SLS_CUS_SER
ii. Composite Role – X: SLS_CUS_SER
- To make a difference between Master role and derived role we can use colon or semi colon can be used
i. Master Role - X: SLS_SER_MGR
ii. Derived Role – X, SLS_SER_REP
There is no definite rule of naming conventions. The above are just guidelines you can mold it your way. But whatever formats you choose to, make it a point that it is consistent, easily identifiable and transparent.