The United States, the Federated States of Micronesia and the Republic of the Marshall Islands have joined in a coordinated stamp issuance.

The United States has issued a pair of 25-cent stamps to commemorate the Compact of Free Association, a treaty that grants political independence to Micronesia and the Marshalls. At the same time, Micronesia issued three 25-cent commemoratives and the Marshalls issued one 25-cent commemorative to honor the occasion.One of the U.S. stamps shows a traditional Micronesian canoe and the national flag of the Federated States of Micronesia. The other depicts a Marshall Islands stick chart and the national flag of the Marshall Islands.

The Marshall Islands and Micronesia stamps and first-day postmarks are available only from their respective philatelic agents. For information about the Marshall Islands issue, contact: Stamps and Philatelic Center of the Republic of the Marshall Islands, 1 Unicover Center, Cheyenne, WY 82008-0021. For information on the Micronesia stamps, contact: Inter-Governmental Philatelic Corp., 460 W. 34th St., New York, NY 10001-2320.

First-day cancellations of the U.S. stamps are available in the usual two ways. The deadline for ordering is Nov. 27.

The Postal Service encourages customers to buy the stamps at a local post office, affix them to self-addressed envelopes and submit them for cancellation to: Customer-Affixed Envelopes, Federated States of Micronesia-Republic of the Marshall Islands Stamps, Postmaster, 900 Brentwood Rd. NE, Washington, DC 20066-9991.

If you want the Postal Service to affix the stamps, send, for each cover desired, a self-addressed envelope and payment in the form of a check or money order for 25 cents for either stamp or 50 cents for both, to: Federated States of Micronesia-Republic of the Marshall Islands Stamps, Postmaster, 900 Brentwood Rd. NE, Washington, DC 20066-9992.The U.S. Postal Service has issued a special pictorial postmark and souvenir folder commemorating New Zealand 1990, the international stamp show held recently in Auckland, New Zealand.

Customers who want to acquire the New Zealand 1990 postmark should affix a minimum of 45 cents postage to a self-addressed envelope, indicate the desired postmark date (Aug. 24 through Sept. 2), and mail in a larger envelope addressed to: Philatelic Sales Division, P.O. Box 449997, Kansas City, MO 64144-9997.

The souvenir folder contains a 12-stamp pane of 25-cent flag stamps, the first to be sold from bank automated teller machines. The folder (Item No. 8817) is available from the Philatelic Sales Division at $4.95. The usual 50-cent handling fee per order and $10 minimum order applies.The Persian Gulf situation has prompted the U.S. Stamp Collectors Society to prepare two exclusively designed covers. One pays tribute to the U.S. armed forces with the message, "Let Freedom Ring Throughout the Middle East." The other honors U.S. hostages held by Iraq with the message, "Hold High the Torch of Hope."

The covers are designed in red, white and blue and cost $9.95. Order from the U.S. Stamp Collectors Society, P.O. Box 854, Van Nuys, CA 91408.Volume III of the 1991 Scott Standard Postage Stamp Catalog is now available. It includes non-British Commonwealth countries of the world, G through O. The softcover edition is $26; the hardcover is $49.95.

Volume IV, P through Z, is scheduled for October release, and the U.S. Specialized for November.

Changes in catalog values reflect actual market changes compared with the previous edition. Retail value is defined as what one could expect to pay for a specific stamp in the stated condition. The greatest number of increases - nearly 700 - in this edition is noted among classic Greek stamps.The Soviet Union is going all out to publicize the joint U.S.-Soviet Creatures of the Sea stamp issuance. The first-day-of-issue program was held with much fanfare at the Moscow Circus. The official ceremony included a special act for the stamps. Soviet television and press gave the event extensive coverage.