In the March 1983 issue of Omni magazine, the International Paper Company presented a two-page advertisement containing various spelling tips by novelist John Irving. To help the bad speller gain confidence, he suggested the following rule:
What about -ary or -ery? Just remember that there are only six common words in English that end in -ery. Memorize them, and feel fairly secure that all the rest end in -ary: cemetery, millinery, distillery, monastery, confectionery, stationery (as in paper).
Eckler, A. Ross
"Silvery Discovery? Glittery Trumpery,"
Word Ways: Vol. 16
, Article 15.
Available at: https://digitalcommons.butler.edu/wordways/vol16/iss3/15