PKG_OPTIONS.apache don't seem to work

[newhouse%rockhead.com@localhost (Paul Newhouse)]

NetBSD mail 5.0.1_PATCH NetBSD 5.0.1_PATCH (MAIL) #21: Mon Jan 18 12:13:24 PST 
2010  root@mail:/usr/obj/sys/arch/i386/compile/MAIL i386

pkgsrc-2009Q3

Installation is in all default locations.

I'm confused about why suexec is found but not apache-shared-modules?

   : grep apache /etc/mk.conf /usr/pkg/etc/mk.conf
   /etc/mk.conf:PKG_OPTIONS.apache  += suexec
   /etc/mk.conf:PKG_OPTIONS.apache  += apache-shared-modules
   /etc/mk.conf:PKG_OPTIONS.apache22  += suexec
   /etc/mk.conf:PKG_OPTIONS.apache22  += apache-shared-modules
   /usr/pkg/etc/mk.conf:PKG_OPTIONS.apache += suexec
   /usr/pkg/etc/mk.conf:PKG_OPTIONS.apache += apache-shared-modules
   /usr/pkg/etc/mk.conf:PKG_OPTIONS.apache22  += suexec
   /usr/pkg/etc/mk.conf:PKG_OPTIONS.apache22  += apache-shared-modules
   
   : (cd www/apache22 && make show-options)
   Any of the following general options may be selected:
           apache-shared-modules   Build all modules as shared for apache22.
           suexec  
   
   These options are enabled by default:
   
   These options are currently enabled:
           suexec
   
   You can select which build options to use by setting PKG_DEFAULT_OPTIONS
   or PKG_OPTIONS.apache.

Looking at other packages I'm wondering where make is looking for these options?

   : grep postfix /etc/mk.conf /usr/pkg/etc/mk.conf
   /etc/mk.conf:ACCEPTABLE_LICENSES+= postfix-license
   /etc/mk.conf:PKG_OPTIONS.postfix += pcre sasl tls

   : (cd mail/postfix-current && make show-options)
   Any of the following general options may be selected:
           bdb      Enable Berkeley DB support.
           ldap     Enable LDAP support.
           mysql    Enable MySQL support.
           mysql4  
           pcre     Enable Perl-compatible regular expressions.
           pgsql    Enable PostgreSQL support.
           sasl     Enable SASL support.
           sqlite   Enable SQLite support.
           tls      Enable TLS support.
   
   These options are enabled by default:
           tls
   
   These options are currently enabled:
           bdb ldap mysql mysql4 pcre pgsql sasl tls

Where have I gone wrong?

TIA,
Paul