Client Expression code appears to reference the Internal Name of other series?

In Demantra version 12.2, the Client Expression code of seeded series appears to reference the 'Internal Name' of other series instead of the 'Series Name'?

     Alternatively interpretation - The underscore character is being substituted for a space?

     Example - the series "End Inv" includes a client expression that refers to "beg_inv"

                    "beg_inv" is the internal name for the series "Beg Inv"

Verifying code confirms that the expression is valid.

This is an interesting change for me as I migrate from version 7.2.

Will this reference return the client value or the server value for the series?

Also, it feels odd that no table reference is required/provided.