The options supported by add-apt-repository are:
-h, --help Show help message and exit
-m, --massive-debug Print a lot of debug information to the command line
-r, --remove Remove the specified repository
-y, --yes Assume yes to all queries
-u, --update After adding the repository, update the package cache with packages from this repository (avoids need to apt-get update)
-k, --keyserver Use a custom keyserver URL instead of the default
-s, --enable-source Allow downloading of the source packages from the repository
In the first form, REPOSITORY will just be appended to /etc/apt/sources.list.
In the second form, ppa:<user>/<ppa-name> will be expanded to the full deb line of the PPA and added into a new file in the /etc/apt/sources.list.d/ directory. The GPG public key of the newly added PPA will also be downloaded and added to apt's keyring.
In the third form, the given distribution component will be enabled for all sources.
On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses.