A clerk at the Department of Housing and Urban Development was given the following instructions on sending out mailgrams to each of the 235 house Democrats who had won reelection: just put down "Honorable" and then "Dear Mr. or Miss."

This week the victorious Democrats got their notes of congratulation from HUD Secretary Patricia Roberts Harris. Each began "Honoable. House of Representatives. Washington, D.C. 20515. Dear Mr. or Miss."

Steve Steinert, HUD's congressional liaison chief, said several House members have telephoned him to ask if HUD knows their sex. "It's an embarrassing thing," Steinert said. "No way I'm going to suggest it was anything beyond that."

Steinert said HUD was anxious that the messages be sent as quickly as possible. "We sent it at night," he said. All night long the obedient HUD clerk sent out the Mailgrams with Harris's messager: "I look forward to assisting you and your staff . . ."

It was not until morning, Steinert said, when a supervisor came on duty, that someone decided that either a "Mr." or a "Mrs." should be dropped, and that it might be nice to add the House member's name.

But then 220 of the 235 Mailgrams had been sent. "We thought about sending a repeat, but then we thought that was silly," Steinert said.

"In all honesty," he said, "we wanted to do a nice thing."