I found one suggestion to use a lower-case() function, as this:
<xsl:sort lang="$lang" select="lower-case(@title)"/>
I tried that but got only a blank report. One source I found for this
says that lower-case() is not available in xsl 1.0.
The XSLT library that Tellico uses only supports xsl 1.0, so all of Tellico's stylesheets stay compatible with that.
I then put in your suggestion from below which works perfectly. I
produces the report I want. It is not an ideal solution for two
reasons. First, it will go away when the next Tellico upgrade is
installed. Second, it gives no option to use case-sensitive sorting if
that is wanted.
My suggestion would be to copy the Group_View.xsl to a new file in the same folder and make the edit. That way it doesn't get affected with the next upgrade and also gives you the option of using either report (with or without sorting).
Robby