collabname in fo/titlepage.xsl?

I am testing <collabname> with pdf output, but do not see any reference 
to the element for fo with either xsl 1.67.2 or even 1.69.0 :

docbook-xsl-1.69.0$ grep -r collabname *
fo/biblio.xsl:<xsl:template match="collabname" mode="bibliography.mode">
html/biblio.xsl:<xsl:template match="collabname" 
mode="bibliography.mode">
html/ChangeLog: * titlepage.xsl: Added collabname in titlepage.mode.
html/titlepage.xsl:<xsl:template match="collabname" 
mode="titlepage.mode">
xhtml/biblio.xsl:<xsl:template match="collabname" 
mode="bibliography.mode">
xhtml/titlepage.xsl:<xsl:template match="collabname" 
mode="titlepage.mode">

however, collab does have an entry in fo/titlepage.xsl

docbook-xsl-1.69.0$ grep -r collab *
common/common.xsl:citerefentry cmdsynopsis co collab colophon colspec 
confgroup
fo/biblio.xsl:<xsl:template match="collab" mode="bibliography.mode">
fo/biblio.xsl:<xsl:template match="collabname" mode="bibliography.mode">
fo/biblio.xsl:<xsl:template match="collab" mode="bibliomixed.mode">
fo/titlepage.xsl:<xsl:template match="collab" mode="titlepage.mode">
.
.
.
Is this a bug?

Cheers,        Tristan
---
Tristan J. Fiedler
Postdoctoral Fellow - Stein Lab
Cold Spring Harbor Laboratory