cat package.mask
>x11-apps/ttmkfdir-3.0.9-r2
>dev-java/sun-jdk-1.5
>dev-java/ibm-jdk-bin-1.5
>dev-db/mysql-3.23.58-r1
>dev-db/mysql-community-5.0.27-r1
>virtual/mysql-5.0

-----------------------------------------------------------

[ebuild     U ] sys-apps/module-init-tools-3.2.2-r3 [3.2.2-r2]
[ebuild     U ] virtual/mysql-5.0 [3]
[ebuild     U ] mail-filter/spamassassin-3.1.8-r1 [3.1.7]
[ebuild     U ] mail-filter/amavisd-new-2.4.5-r1 [2.4.4] USE="-courier% -qmail%"
[ebuild     U ] dev-lang/php-5.2.1-r3 [5.1.6-r8] USE="-calendar* -filter% -ftp* -iconv* -json% -ldap-sasl% -mcve* -odbc* -pdo* -spell* -suhosin% -wddx* -xmlreader* -xmlrpc* -xmlwriter* -xpm* -xsl* -zip* -zip-external%"
[ebuild     U ] mail-mta/postfix-2.4.0 [2.3.6] USE="-dovecot-sasl* -ipv6* -sasl* -vda*"
[blocks B     ] dev-db/mysql (is blocking dev-db/mysql-community-5.0.27-r1)