1. When Emerge -UD World, I want a software to not upgrade.
The name of the package included in the / var / lib / portage / world file is defined, such as NET-WWW / Mozilla assumes that you install Mozilla is 1.7.5 and there are 1.80-beta1 in the upgrade list but you don't want to Upgrade, change the above sentence to NET-WWW / = Mozilla-1.7.5 means that the Mozilla in the fixed world is 1.7.5.
