Skeleton file
From FreeBSDwiki
/etc/skel is the directory that is used as a template when adding users; skeleton files can also be located in /usr/share/skel/ with filenames in the format "dot.filename" (e.g., dot.cshrc) which when copied over to a new user (by using adduser) they will be renamed without the "dot" prefix. If you want to give users a particular shell's .profile, such as .bashrc or .cshrc to create a customized shell with special PATH or alias entries, add it here, as any file in /etc/skel will be copied over to a new user that is created.