(1 to the square root of 2) are not recommended. (4) Window envelopes. Window envelopes, or open panel envelopes, may be used under the following conditions: (i) The address window must be parallel with the length of the envelope. (ii) The proper place for the address window is in the lower portion of the address side. (iii) Nothing but the name, address, and any key number used by the mailer may appear through the address window. (iv) The return address should appear in the upper left corner. If there is no return address and the delivery address does not show through the window, the piece will be handled as dead mail. (v) The address disclosed through the window must be on white paper or paper of a very light color. (vi) When used for registered mail, they must conform with the conditions in § 161.3(c). (vii) Window envelopes, but not open panel envelopes, may be used for business reply mail provided: (a) All of the address side except the portion which will show through the window is prepared as required by § 131.2 (c) (4). (b) An address prepared by any of the processes and in the style provided for by § 131.2(c) (4) is furnished by the distributor for use as an enclosure to return the envelope. (c) The window covering is of such texture as to allow maximum transparency. (b) Plain stamped envelopes-(1) Envelopes available at post offices. NOTE: Limit requisitions to a 6-week supply. A minimum quantity of 500 plain stamped envelopes must be ordered even though this may cause some post offices to exceed the 6-week stock level. (2) Sales at Post Offices. Only sizes 64 and 10 regular and airmail will be sold in less than full box lots. Boxes contain 500 envelopes. (3) Discount on sales of plain regular and airmail stamped envelopes.-(i) Definition. Plain regular and airmail envelopes are charged to and carried on post office records at the amounts specified in Handbook F-1. Sales to customers are made at the rates specified in paragraph (b) of this section. This results in sales of 500 and multiples thereof out of the main stock or fixed credits being made at a discount. (ii) Recording discount. A record shall be kept of each bulk sale of 500 lots of plain regular and airmail envelopes. Use Form 3220, Stamped Envelope Sales at Discount. As each sale is made record the date, purchaser's name, and quantity sold. The selling employee will obtain the purchaser's name from the check used for payment or by asking when payment is by cash. Do not refuse sales to those who decline to identify themselves. State purchaser declined identification in the name column. Enter the quantity in the proper size and denomination column. (iii) Reporting discount. Employees selling 500 lots may complete Form 3220 as often as necessary, but at least each accounting period at first-class offices and each postal quarter at other classes of offices in time for the discount to be included in a regular requisition submitted during the same period or quarter. The total amount of the discount claimed must be included in the total amount of the regular requisition for stock. Submit this requisition to the custodian of the main stock. The station superintendent or an employee in a similar capacity must verify the computations on Form 3220, enter his initials and submit the form direct to the direc tor, office of finance, chief accountant or employee maintaining the cashbook as specified in Handbook F-1. (4) Precanceled envelopes. Only nonprofit organizations or associations covered in § 134.5 may purchase 1.7-cent precanceled envelopes. Sales are made in full box lots only. (5) Window envelopes. Window envelopes are sold in full box lots only. All windows are 1% inches wide and 434 inches long and are located one-half inch from the bottom of the envelope. In size 634, the window is located seveneights inch from the left edge, in size 10 it is three-fourths inch from the left edge. (6) Dimension of envelopes. Size 64Size 10. 35% by 61⁄2 inches 4% by 91⁄2 inches (Dimensions may vary 16".) (7) Private printing of return addresses. Stamped envelopes may be privately printed in any style, provided at least 31⁄2 inches of clear space is left at the right end of the address side of the envelope. § 141.2 (c) Postal cards available. Denomination (cents) 6--9 10-- 15___ Description Cut Single Cards: Domestic regular single (available Domestic commemorative single. Foreign regular single, 31⁄2" x 51⁄2" Domestic regular reply (6 cents each half). All domestic (regular and airmail) postal cards are precanceled. Postal cards in sheets for use in printing must be cut to regulation size, 34 x 51⁄2 inches so that the stamp appears in the upper right corner. However, domestic regular and domestic airmail cards may be cut to 3 x 5 inches. Cases of sheet postal cards may be broken for sale. Return addresses are not printed on postal cards by the Postal Service. Domestic regular and airmail postal cards are not acceptable for foreign mailings. Only cards which measure 31⁄2 x 51⁄2 inches may be used. (d) Aerogrammes. 15 cents each. (See Publication 42, International Mail.) [35 F.R. 19446, Dec. 23, 1970, as amended at 37 F.R. 17830, Sept. 1, 1972] Printed stamped envelopes (special request). (a) Printed stamped envelopes available. 1 Minimum order-Please note that the price for 500 only is more than 1⁄2 of the per-thousand price. (b) How to order printed stamped envelopes. Prepare Form 3203, "Order for Printed Stamped Envelopes," as illustrated below. Submit the order through the post office named in the return ad dress. However, if undeliverable letters are to be returned to the main office of a firm in another city, envelopes may be ordered at the post office where they will be mailed. CAUTION: ILLEGIBLE OR INCORRECT ORDERS DELAY RECEIPT OF ENVELOPES (c) Style of printing return address. (1) All lines of the return address will be printed in capitals and lower case letters with flush left margin using 8point Helvetica type. (2) Sample style of printing: Charles Jones 610 Seventh Avenue New York, NY 00000 (d) Required printing-(1) Local address. The printed address must include the local address. The adequacy of the address, to insure return of undeliverable mail, will be determined by the postmaster. Any one of the following may be used: (i) Street address. (ii) Post office box number. (iii) Rural route number and box number. (iv) Name of building and room number, including street address. (v) A street address and a post office box number may be shown in the return address. When both addresses are shown, mail will be returned to the address indicated in the line immediately preceding the city, State, and ZIP code. The ZIP code must be that of the delivery unit serving the address shown in the line immediately preceding the city and State. (2) Name of post office. The printed return address must include the name of the post office or branch post office, State and ZIP Code. (e) Optional Printing-(1) Name. (i) The name may be that of an individual, associafirm, corporation, institution, tion, or society. It may include the name and title of an officer of the concern (as John Doe, Treasurer, Washington Educational Association) and such titles as M.D., D.D.S., Rev., and L.L.D. (ii) Descriptive words, such as "Druggist", "Attorney at Law", "Esquire", or "C.P.A." are not considered titles, but represent business or professional names, which may also be printed. Such descriptive words are printed subject to the conditions set forth in paragraph (e) (2) of this section. (iii) The name of a branch or department of a business may be printed only when necessary to insure return of undeliverable mail, i.e., when other branches or departments are located at the same post office address. (2) Advertising. (i) A brief statement or descriptive phrase devoted to advertising may be printed either following the name or on a separate line. There may not be more than two such lines devoted to permissible advertising matter. (ii) An individual or organization engaged in business, professional, educational, social, cultural, charitable, political, or other endeavors, may advertise. The advertisement may describe the nature of the business of the individual or organization or refer to the goods, services or works provided by the individual or organization. (iii) Statements or descriptive phrases which describe the nature of a business and contain a reference to the quality of the goods or services produced such as "Best Tires in Town" or "Complete Insurance" will be permitted. (iv) Nothing will be printed which would make the envelope nonmailable under 18 U.S.C. 1463, which prohibits the mailing of indecent matter on wrappers or envelopes. (3) Phone numbers. The phone number of any individual or group may be printed on the envelope. (4) Postal instructions. Only the postal instructions in this section may be included as part of the printed return address. "The request to return endorsement of § 141.2(a) (4) (i) shall appear above the name and address." All other postal endorsements shall appear below the line with the city, State, and ZIP Code. A combination of endorsements may be used. (i) Request to return. A request to return undelivered mail after a specified number of days (not less than three and not more than 30) may be printed. If a return request is included on envelopes for third-class mail the words "Return Postage Guaranteed" must also be used. Sample printing: After 5 days, return to: (ii) Address correction. A request for address correction service may be printed on mail of any class. The new address of addressee or the reason why the piece is undeliverable will be furnished. See § 159.2(d) (3) for the charge. Sample printing: Address Correction Requested: (iii) Third-class mail. On single piece rate third-class mail which is sealed (see also § 134.8), the following must appear: Third Class: (iv) Return of undelivered third-class mail. A request may be made to return undelivered third-class mail. See § 159.2 (d) (1) for the charge. Sample printing: Return Postage Guaranteed: (v) Forwarding third-class mail. A request to forward third class mail to a new address may be made. If addressee refuses to pay forwarding postage, the mail will be returned, and both forwarding and return postage will be collected from the sender. See § 159.2 (d) (2) for charges. Sample printing: Forwarding and Return Postage Guaranteed: (f) Other requirements. (1) No line of either required or optional printing may exceed 47 characters and spaces. (2) The total number of lines of required and optional printing may not exceed seven. (3) The last two lines of printing shall be reserved for the street address or P.O. box number where mail is to be delivered, and the city, State, and ZIP code. (g) Prohibited printing. No matter may be printed other than that permitted by paragraphs (d) and (e) of this section. (h) Rejection of envelopes. Specialrequest envelopes may be rejected because of defective manufacture, or mistakes in printing, denomination, size, etc. If the mistake was made by the purchaser, the value of the postage only will be returned. If the mistake was made by the post office or its contractor, the entire invoiced value of the envelopes will be returned. [35 F.R. 19446, Dec. 23, 1970, as amended at 37 FR 17830, Sept. 1, 1972; 38 FR 22384, Aug. 20, 1973] Ordinary postage. Single or sheet. Commemorative stamps. Airmail postage (for use on airmail only. See 141.12). Precanceled postage. Postage-due (for post office use only). Denomination and prices 1, 2, 3, 4, 5, 6, 8, 10, 12, 13, 14, 15, 16, 20, 25, 30, 40, and 50 cents; $1 and $5. Books..... 32 6-cent & 8 1-cent ($2)* 25 8-cent ($2). Coil of 100... 6,* 8, and 25* cents: (Dispenser to hold coils of 100 stamps may be purchased for 5 cents additional.) Special delivery. (See part 166.) Single or sheet. 1, 2, 5, 6, and 8 cents. 25 cents. Various denominations 8 11-cent & 6 2-cent Available to permit 1, 2, 3, 4, 5, 6, 7, 8, 10, 30, and 50 cents; $1 and $5. 60 cents. Good only for special delivery fee. * Will be discontinued when stock is exhausted. (b) Use. (1) Use stamps of the highest suitable denomination. (2) Fix stamps firmly in the upper right corner of the address side of the mail cover. (3) Any stamp partly concealed by an overlapping stamp may not be counted as postage. (4) Postal employees (other than rural carriers as prescribed in § 156.4(a)) are not required to fix stamps to mail. (5) Airmail postage stamps may be used to pay fees for special services on airmail articles. (6) The $1 airlift stamp may be used to pay the airlift fee on PAL parcels (see § 126.1(e) (3) of this chapter) or it may be applied as payment, in whole or in part, of the amount of the postage charges or fees for special services on airmail articles. (c) Perforating. Postage and special delivery stamps may be perforated with an identifying mark if the holes do not exceed one thirty-second of an inch in diameter and if the space taken by the mark is not larger than 1⁄2-inch square. (d) Reuse prohibited. Reuse of stamps with intent to cause loss to the Government is punishable by fine and imprisonment. [35 FR 19446, Dec. 23, 1970, as amended at 38 FR 22384, Aug. 20, 1973] § 142.2 Purchase of postage. (a) Acceptable form of payment. Foreign or mutilated money is not acceptable. When the post office cannot make change, the exact amount of the purchase must be paid. Postal employees are not required to accept personal checks. To send money by mail, use money order or certified check. (b) Purchase receipts. If the customer wants a receipt for purchases and has prepared the receipt in advance, the postal employee will stamp it upon payment. If the customer has not prepared but wants a receipt for purchases, a Form 1096, Cash Receipt, will be used for postage and other services for which verification of payment is not already provided. The postal employee will fill in the total amount of the purchase and will stamp the form upon payment. (c) Postage due. Postage due must be paid in cash. Postage-due stamps may not be used for paying postage. [35 F.R. 19446, Dec. 23, 1970, as ainended at 37 FR 15304, July 29, 1972] § 142.7 Validity of stamps. All postage stamps issued by the United States since 1860 are good for postage from any point in the United States or from any other place where the U.S. domestic mail service operates, except from the Panama Canal Zone where special Canal Zone stamps are used. The following are not good for postage: (a) Mutilated or defaced stamps. (b) Stamps cut from stamped envelopes, aerogrammes, or postal cards. (c) Stamps covered or coated in such manner that the canceling or defacing |