BuddyPress.org

Stopped being lazy and read the code.

Firstly, I wasn’t paying attention to the “domain” of the strings I was translating, which seemed to be in both buddypress and the theme.

BuddyPress language file had to be under wp-content/plugins/buddypress/bp-languages/, and be named buddypress-%locale%.mo (and .po) where %locale% is the configured locale, such as en_US

The theme (from WPMUDev) had its own language files/domain, and those had to be in the theme’s language directory, and called %locale%.mo (and .po), and then a comment in the theme’s functions.php instructed me to:
`/* uncomment if using custom mo / po file
function init_theme_localization( $locale ) {
return “en_US”; //must be same mo or po name in theme languages folder..it could be en_US or bp-en_EN etc
}
add_filter(‘locale’,’init_theme_localization’);
*/`

Phew!