This is a weird and confusing user experience. I’d say that either:
an error should be displayed when starting a parent shortcut name with a non-alpha character, or
the ‘paste reference’ context command should escape it appropriately.
while the parameter itself is just a string parameter and therefor won’t evaluate or sanity check the input, the containing operator should go into an error state and not only any reference to the invalid Parent Shortcut:
The background to this being an invalid identifier goes back to python itself and the inability of python to recognize identifiers as such if they start with a number. Python would try to use the identifier as a numeric literal but fails when encountering the characters. Why this is tricky for python is that numeric literals can contain non numeric literals like e for exponent, _ for delimiting, or x for hex and more…