Hi Mark,
As you know its a filter name in advantage search area, i couldnt find its string so added these below, i tougth that it must be one of them below and added them in my lang file. It didnt worked, so must be an inline string or something. that is not a big issue, It just was a not for you...
COM_EASYSOCIAL_SEARCH_TYPE_ARTICLE=
COM_EASYSOCIAL_SEARCH_TYPE_ARTICLES=