When a reference name is not enclosed in quotes and contains an invalid character, then it should trigger Cite error ref too many keys. Example:
<ref name = smith p1>x</ref>
But, if the the name fragment after the space contains (not just begins) any other character than A–Z, a–z, 0–9, then the error is not triggered. Example:
<ref name = smith p!1>x</ref>
This should generate the error message, but instead it truncates the name at the space.