Markus Hoenicka wrote
> An alternative notation of the content model could be written
> like this:
> msIdentifier := block1, block2
> block1 := sequence|msname
> block2 := altIdentifier|msName*
block2 := (altIdentifier|msName)*
> sequence := placeName? , bloc? , country? , region? ,
> district?, settlement? , offset? , geogFeat? , institution? ,
> repository , collection? , idno?
The trouble is that <repository> is given without the '?' quantifier
thus making it mandatory if any other element from sequence is
present. This is confirmed by the validator: as long as there's a
<repository>, anything goes. I don't think this omission of
the '?' quantifier in ROMA is intentional, though.