It might also mean having teaching materials in elementary schools that don't just include pictures of London or New York or Sydney or Toronto, etc. ELF is about widening ELT (English Language Teaching) beyond the Big 6 countries. As you probably know, carrying a passport of one of these Big 6 countries mean you're assumed to be proficient in English by virtue of having attended elementary / high school in these countries, which means you can apply for jobs, be admitted to unversity without any of the red tape and expense involved in officially demonstrating English proficiency.
A school or teacher talking about ELF might also mean "English for Global Communication" i.e. for business and study purposes. This sometimes includes a focus on 'Plain Language' i.e. speaking in clear and simple terms, in an honest way, out of respect for people whose first language is not English. This comes from the growing population of very proficient English speakers who still struggle (will likely always struggle) with the nuances of very fluent English -- but whose economic clout to demand that monolingual English speakers learn how to communicate *with* second language speakers (and not communicate over their heads, for business advantage, for example)
Plain Language Initiatives (as I understand them) are politicized in that they're putting more onus on 1) making native speakers accountable for how they use language in international settings, and raising their awareness / skills and 2) getting learners to focus a little more on negotiating meaning (meta-communication) rather than thinking (absolutely erronously, IMHO) that more and better phrasal verb mastery is what they need. So, to sum up, ELF is about presenting English communication as something that happens between individuals from everywhere -- with less emphasis on countries or populations as 'owners' of the language or mediators of what is right, or not.
Just some thoughts --
EFL means instruction for people learning where English is not the lingue franca, and traditionally this meant a focus on (academic) test preparation (for overseas study or travel or immigation)
whereas
ESL is for people trying to survive and thrive in an English-speaking country and includes more immediately practical topics (transportation, banking, workplace language, renting a flat, words for household objects and things in the neighbourhood), functions (expressing disagreement, negotiating, meeting new people) and skills (reading schedules, talking to store clerks and buying things, using ATMs, listening to lectures (listen, listen, listen, make some notes, listen, listen) vs participating in interactive conversations (speak, listen, speak, listen more, speak, speak)
ELF is a new term that is in vogue these days, reflecting the growing understanding that no one 'owns' English (i.e. no accent is superior -- long overdue and a relief to a lot of people whose first language is English but don't have a pasport from the six so-called 'English-speaking countries') and that 'native speakers' are not the only valid sources of language input / are not the final word on what is 'correct' usage. A lot of Nigerians, for example, learn English in school from the very beginning and are fluent/native, although with an accent. Why isn't that accent as accepted as other accents? Well -- good question and that is part of what ELF is about as a school of thought about how English should be taught. In practical terms, it might mean including speakers with an Indian accent or a Nigerian accent in official listening materials for high stakes exams, for example. (That is a big wow -- imagine forcing millions of learners to come to grips with other accents -- that has huge implications for what is taught in schools, for the business of high stakes language teaching, etc)
