If a SAP Gateway system and/or one of the connected backend systems is a non-unicode system certain technical restrictions need to be considered:
If the name of an EDM artifact (that is, a name of an artifact of the service’s EDM model, for example, a property name) contains characters that are not in the system code-page, then the following applies: Such characters are converted into the hash character - #.
This results in an error during the name validation in the OData library.
The origin of such EDM names could, for example, be the Service Builder or OData services generated with SAP Gateway.
If the data (for example, HTTP request/response payload) from a unicode system or unicode clients contains characters that are not in the system code page, then the following applies: A conversion into STRING is done which converts characters that are not available in the system code-page into the hash character - #.
This does not necessarily result in an error.
The origin of such data could, for example, be applications on the basis of the UI development toolkit for HTML5 (SAPUI5) or external OData services in a client scenario.
It is highly recommended that both the SAP Gateway as well as all connected backend systems are unicode systems.
The above listed issues can be overcome by exclusively using characters that are in the code-pages of all systems. Depending on the support package stack level at least the following SAP Notes have to be applied as well: