2.2.10 [W3C-XSLT] Section 7.4, Creating Comments

C0013:

The specification states:

 It is an error if instantiating the content of xsl:comment creates nodes other than
 text nodes. An XSLT processor may signal the error; if it does not signal the
 error, it must recover by ignoring the offending nodes together with their content.

MSXML3 and MSXML6

The offending nodes and their content are ignored.

C0014:

The specification states:

 It is an error if the result of instantiating the content of the xsl:comment
 contains the string -- or ends with -. An XSLT processor may signal the error; if
 it does not signal the error, it must recover by inserting a space after any
 occurrence of - that is followed by another - or that ends the comment.

MSXML3 and MSXML6

A space is inserted after any occurrence of a "-" that is immediately followed by another "-". That is, a space is inserted between a "-" and a "-". The result is "- -".