[MEI-L] order of elements

[Johannes Kepper]

Dear MEIers,

this is a somewhat technical question, but I guess of interest to nearly everyone who's producing MEI, either by hand or by software. The current schema of MEI enforces a certain order of child elements for large parts of the header. For instance, you may write 

<source>
	<titleStmt>…</titleStmt>
	<notesStmt>…</notesStmt>
	<relatedItem>…</relatedItem>
</source>

but not 

<source>	
	<notesStmt>…</notesStmt>
	<titleStmt>…</titleStmt>
	<relatedItem>…</relatedItem>
</source>

or any other order like

<source>
	<titleStmt>…</titleStmt>
	<relatedItem>…</relatedItem>
	<notesStmt>…</notesStmt>
</source>

This is somewhat cumbersome when adding header elements on the fly, as you always have to check for the correct place for insertion. This is surely a technical issue without any semantic reason behind, so I'm wondering if there is a way around that. Could someone with more experience in ODD and the other schema languages provide some more background on this? Raffaele?

Thanks,
Johannes