[from the note to the poem in The Collected Poems of William Carlos Williams, volume 1, 1909-1939, edited by A. Walton Litz and Christopher MacGowan:]
Florence Williams's "reply" to "This Is Just to Say" is included as a "Detail" in the partially published Detail & Parody for the poem Paterson [a manuscript at SUNY Buffalo]; it first appeared in The Atlantic Monthly (November 1982), p. 145. Since WCW chose to include the reply in his own sequence it seems likely that he took a note left by his wife and turned it into a "poem."
The following text is taken from a typescript [also in the Buffalo archive]:
(crumped on her desk)
Dear Bill: I've made a
couple of sandwiches for you.
In the ice-box you'll find
blue-berries--a cup of grapefruit
a glass of cold coffee.
On the stove is the tea-pot
with enough tea leaves
for you to make tea if you
prefer--Just light the gas--
boil the water and put it in the tea
Plenty of bread in the bread-box
and butter and eggs--
I didn't know just what to
make for you. Several people
called up about office hours--
See you later. Love. Floss.
Please switch off the telephone.