In
t0mpr1c3 points out that srl:sxml->xml does not appear to perform any validation to ensure that the tag names used conform to legal xml names (IIUC, this is the "NCName" production in the W3C's XML recommendation:
https://www.w3.org/TR/REC-xml/#NT-Name
Generally speaking, this seems like the kind of thing that Oleg et al. get right, so I'm hesitant to call this a bug without digging a little deeper. Anyone know if there's a good reason why srl doesn't perform this validation? (I've also written to Oleg, though I'm not sure I still have a good email address for him.)