Letters that make self-contained
s, a, o, d, e, f, l, n, c, t, i are letters that make 'self-contained'
Words within self-contained
el, LF, NT, ELF, SE, contain, ED, EL, contained, on, ain, self, Tai, con, in, AI, ai, CO, IN, NE, elf, Co, In, Ne, Se, Ta are words within 'self-contained'