A second edition, OSPD 2, was released in 1991. The current edition is OSPD 7, released in November 2022.

Ew joins another 106 two-letter words, which are aa, ab, ad, ae, ag, ah, ai, al, am, an, ar, as, at, aw, ax, ay, ba, be, bi, bo, by, da, de, do, ed, ef, eh, el, em, en, er, es, et, ex, fa, fe, gi, go, ha, he, hi, hm, ho, id, if, in, is, it, jo, ka, ki, la, li, lo, ma, me, mi, mm, mo, mu, my, na, ne, no, nu, od, oe, of, ...

Collins is the only online Scrabble word checker to use the official tournament word list, including over a quarter of a million permissible words. It's endorsed by Mattel and the World English-Language Scrabble™ Players' Association.

Oxyphenbutazone is an anti-inflammatory drug and a recognized word in the Scrabble dictionary. It is theorized to be the highest scoring legal word that would actually fit on a Scrabble board.