None.
source file
Read and execute commands from file file. Source commands may be
nested to a maximum recursion level of ten. If file is not an absolute
path and screen is already processing a source command, the parent
directory of the running source command file is used to search for the
new command file before screen's current directory.
Note that termcap/terminfo/termcapinfo commands
only work at startup and reattach time, so they must be reached via the
default screenrc files to have an effect.
source .screenrc-$HOST
Loads a host-specific .screenrc file. This assumes an environment variable named $HOST, which is not standard on all systems.
bind l source $HOME/layout
Binds the sequence C-a l to load a .screenrc-type file named “layout”.
This might set up the display in particular ways. Sourcing a file can be
a more convenient way to run several screen commands than using
eval.