About language files

[hkweb]

If I would like to develop my language file
which and where should I modify?

is that simple to create my own language file under /whmcs/lang ?
or any other place I need to modify/add file?

thank you so much

[MACscr]

http://v3manual.whmcs.com/display.php?id=23#

[hkweb]

thanks, I got it.