Updated May 13th: Here is the first-day Digital Color Postmark for this issue: size: 2.47″ x 1.23″. The Black & White or “rubber” postmark is the standard FDOI 4-bar.

Updated April 15 from the Postal Bulletin:
On May 18, 2015, in Anaheim, CA, the U.S. Postal Service® will issue the Missing Children First-Class Mail® Forever® stamp, in one design, in a pressure-sensitive adhesive (PSA) pane of 20 stamps (Item 473100).

The stamp will go on sale nationwide May 18, 2015.

Affirming its long-standing commitment to help find missing children, the U.S. Postal Service® issues this new stamp to make the public more aware of the ways they can assist — and to offer hope to families as they continue their search. The stamp features a photograph by Harald Biebel showing a small bunch of purple forget-me-nots alongside a single flower. Text at the top of the stamp reads “FORGET-ME-NOT.” Text along the bottom of the stamp reads “HELP FIND MISSING CHILDREN.” The pane’s verso text discusses this important issue, describes the program that delivers materials featuring photos of missing children to millions of American homes, and provides con­tact information for the National Center for Missing and Exploited Children. Art director Ethel Kessler designed the stamp.

How to Order the First-Day-of-Issue Postmark:
Customers have 60 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office, at The Postal Store® website at www.usps.com/shop, or by calling 800-STAMP-24. They should affix the stamps to envelopes of their choice, address the envelopes (to themselves or others), and place them in a larger envelope addressed to:

Missing Children Stamp
Postmaster
Anaheim Post Office
701 North Loera Street
Anaheim, CA 92803-2282

After applying the first-day-of-issue postmark, the Postal Service will return the envelopes through the mail. There is no charge for the postmark up to a quantity of 50. For more than 50, customers have to pay five cents each. All orders must be postmarked by July 17, 2015.

There are eight philatelic products for this stamp issue:

• 473106 Press Sheet with Die-cut, $58.80 (print quantity 500)
• 473108, Press Sheet without Die-cut, $58.80 (print quantity 1,500)
• 473110 Digital Color Postmark Keepsake, $11.95
• 473116 First-Day Cover, $0.93
• 473121 Digital Color Postmark, $1.64
• 473130 Ceremony Program, $6.95
• 473131 Stamp Deck Card, $0.95
• 473132 Stamp Deck Card with Digital Color Postmark, $1.99

Technical Specifications:

Issue: Missing Children Stamp
Item Number: 473100
Denomination & Type of Issue: First-Class Mail Forever
Format: Pane of 20 (1 design)
Series: N/A
Issue Date & City: May 18, 2015, Anaheim, CA 92803
Designer: Ethel Kessler, Bethesda, MD
Art Director: Ethel Kessler, Bethesda, MD
Typographer: Ethel Kessler, Bethesda, MD
Existing Photo: Harald Biebel
Modeler: Joseph Sheeran
Manufacturing Process: Offset, Microprint
Printer: Ashton Potter (USA) Ltd. (APU)
Printed at: Williamsville, NY
Press Type: Muller A76
Stamps per Pane: 20
Print Quantity: 60 million stamps
Paper Type: Nonphosphored Type III, Block Tag
Adhesive Type: Pressure-sensitive
Processed at: Ashton Potter (USA) Ltd. (APU)
Colors: Black, Cyan, Magenta, Yellow, PMS 159 Orange
Stamp Orientation: Horizontal
Image Area (w x h): 1.42 x 0.84 in./36.07 x 21.34 mm
Overall Size (w x h): 1.56 x 0.98 in./39.62 x 24.89 mm
Full Pane Size (w x h): 7.24 x 6.20 in./183.90 x 157.48 mm
Press Sheet Size (w x h): 21.72 x 12.53 in./551.69 x 318.14 mm
Plate Size: 240 stamps per revolution
Plate Numbers: “P” followed by five (5) single digits
Marginal Markings: Front: Plate numbers in two corners of pane 
• Year of Issue • Header “Help Find Missing Children”
Back: © 2015 USPS • USPS logo • Plate position diagram • Barcode (473100) in upper right and lower left corners of pane • Promotional text • Verso text

Updated April 1 from the Postal Bulletin: There are now also stamped envelopes with this design. The first-day date is May 18th.

From the USPS Conference Call February 20th:
May 25th is Missing Children Day but that date has not yet been confirmed. Pane of 20. The Forget Me Not flower shown on the stamp is the symbol of the campaign. More from the USPS:
This public service message stamp features forget-me-nots. This flower is the symbol used for International Missing Children’s Day.

The photograph on this stamp was taken by Harald Biebel. Ethel Kessler was the art director and designer.

This is the second stamp to bring attention to this issue. In 2006, the USPS issued the AMBER Alert stamp.

This stamp is intended to make the public more aware of ways they can assist in helping find our Missing Children. It offers hope to the families of missing children as they continue their search.

Since 1984, the National Center for Missing and Exploited Children has helped law enforcement recover more than 205,000 missing children.

The recovery rate for missing children continues to increase, thanks to greater public awareness, law-enforcement training, laws, and technology.

May 25 is National Missing Children’s Day. It is also International Missing Children’s Day.