Re: Trouble using xsl:key under XSL 1.0

<xsl:key name="playerResultLookupByWeek" match="playerResult[../@week=$week]" use="@player" />

A big thing to watch out for here - the xsl:key match must be a pattern,
which is required to be context-free. (Same as the match pattern in
xsl:template.) And one of the big limitations to patterns is that you
cannot have variable references inside them. Even if the variable is
top-level, and even if it's something simple like
document('')/*/someElement, it can't be used in the match pattern.

Learn to start thinking around variables in your keys, and you'll end up
banging your head against the wall less often. :)

Cheers,
-- Abel Braaksma