In the latter days of October, there arrived at my home a manila envelope that bore the return address "Internal Revenue Service."

My ersatz heart skipped a beat and my hand shook as I opened the envelope. A thousand possibilities - all grim - raced through my head. What had I done wrong? How much would my mistake cost me? Can a taxpayer plead insanity, or does that work only for murderers? Could IRS possibly be writing to tell me I had sent in too much, and would therefore be getting a rebate? Hah!

Inside the manila envelope I found a form letter that said IRS was having trouble identifying me. It couldn't relate my income tax return to a certain broker's report of his transactions with me under a phony Social Security number. Would I please apply for an honest number and tell IRS about it when it was issued?

As soon as my heartbeat steadied, I saw what had gone wrong. The broker's clerk had changed one of the nine digits in my Social Security number from a 9 to a 4.

I filled out the form and sent it off, so relieved that I didn't even protest being forced to pay 15 cents in postage to correct somebody else's error.

And when a letter arrived from Philip S. Brown a few days later (on Nov. 6), I was in a position to read it with great sympathy.

Brown's heart palpitations had been occasioned by the arrival of a ukase from the Tax Administration of the District of Columbia's Department of Finance & Revenue. In boldfaced capital letters, this communication said, "NOTICE OF ADJUSTED D.C. INCOME TAX RETURN." Arrrgh!

The code number I identified what "type of notice" this was: an "Adjusted balance due. (Deficiency in tax) Your tax liability has been increased due to error(s) on your tax return." Below was a line for "Reason Code(s). Refer to explanation of adjustments on reverse side."

There were three columns of dollar amounts: Column A, Column B and "Adjusted Balance Due." The reason code for Column A was "R" and the reason code for Column B was either a 3 or an 8. The digit had been printed on the lines in the lower right-hand corner of the box provided for it instead of in the center of the box, and was therefore illegible.

However, this was of little consequence because there were no digits of any kind explained on the back of the form, only letters B through Z. The reason code R was given as, "Improper property tax credit or refund," and the "balance due" for that sin was listed as $155.50. The "balance due" for the unfathomable 3 or 8 code in Column B was $462.40, and the two together added up in the "Adjusted Balance Due" column to $9.90 - which boldfaced capital letters said was NOT to be remitted!

If the District of Columbia wasn't asking for additional payment, what was the purpose of this notice? What did the figures mean? How had they been computed? What error had Brown made with regard to his property tax? Did Brown have the right to choose one from Column A and one from Column B, or was this some new kind of Chinese puzzle?

Brown wrote to me and sent copies to Polly Shackleton and Del. Walter Fauntroy. Shackleton and Fauntroy forwarded the photostats to Mayor Walter Washington. I was unable to establish what the mayor did with them, but I do know what I did. I called a nice man at the D.C. Department of Finance and Revenue.

The nice man looked up Brown's account and said, "Oh, we made a mistake. There was no error in Brown's property tax credit; he just made a simple error in addition and we wanted him to know that in due course he would get a tax bill for $9.90. We are getting in touch with him to explain all this, so you can just dismiss it from your mind."

I told him I would dismiss it from my mind, which was a lie. I also told him I thought his tax form and notification procedures were absurd, which was the truth.

On Sunday night, Nov. 26, the letter from District Liner Brown came up for review in my homemade tickler system, and I phoned Brown to ask whether everything had been straightened out to his satisfaction. "I was told," I said, "that I could dismiss the matter from my mind because the tax people would get in touch with you. Did they?"

"No," he said. "I haven't heard a word from them. But if the District sent out a few thousand other tax forms like the one I received. I have a pretty good clue as to why Walter Washington was defeated."