Assigning Names for Standard and Customer Schemas 
Use
You can create your own schemas or change existing schemas to adjust them to individual requirements. The assignment of names for standard and customer schemas describes how you should call your newly created or changed schemas.

We recommend that if you change a schema, you also change the name of the schema and do not use the SAP standard name. It is then easier to recognize where in your system changes have been made to schemas.

If you give a schema a name that is not compatible with the name of the standard schema, you must change the schema access point in the main schema or subschema accordingly.
Name Assignment
No actual name range definition exists for the personnel calculation schemas. This means that existing customer schemas can, in principle, contain all available characters as part of their name. However, if you want to newly create schemas, special characters are no longer permitted. Whether a schema name may contain a certain special character or not is only relevant if you want to create a new schema.
If you process a schema with a non-permitted special character in the name, the system shows a warning message. You do not need to change this name, however we do recommend that, in the long term, you modify your schema names in line with the name assignment rules described here.
Permitted and Non-Permitted Special Characters
You should bear the following in mind when assigning names: