The first two following questions were originally reported to me by my programmer, Eugene Fotin.

While implementing the new xsl:merge syntax, we stumbled upon the following questions, to which I believe the specification has no clear answer:

> what error should be raised if both @for-each-stream and @for-each-item are present? 

I think that, in line with similar constructs that have mutual exclusive attributes, we should introduce a specific static error condition for this.

> what to do when @for-each-stream is present and streamable="no" or is absent?

From the current text, the semantics of for-each-stream are described in terms of streamability. I think that in the case of the effective value of streamable="no", the behavior should be similar to the fn:collection function (except that its arguments do not return collections, the behavior is more like fn:document), i.e., whether or not it is stable is implementation dependent. If we mean that, I think we should say so explicitly.

> the type of @for-each-stream is xs:string*, however the spec demands it to return uris, in fact, this is a MUST. Making it just xs:string* seems too liberal.

Why not change the argument to be xs:anyURI*? Then a type error would be the logical error if an argument is not a URI.

> the behavior of dereferencing the uris is described as the same as fn:doc. Does this preclude raising the same errors if dererencing fails? (this remark also applies to xsl:stream, which defines no errors of its own).

We are more explicit about error conditions with fn:streaem-available, stipulating the errors of fn:doc-available that it inherits. I think it is worth mentioning this for xsl:stream and xsl:merge/@for-each-stream as well.