This Technical Specification defines a set of physical marks called Address Block Locators (ABLs). ABLs are marks, printed in the vicinity of addresses on postal items, that are intended to facilitate automatic recognition of address location and processing of the addresses on mail sorting and video-coding equipment. The Technical Specification describes two families of ABLs which may be printed on all types of postal items, including letters, flats and parcels. In the first family, address block locators take the form of pictograms which bear no other information than being a landmark for the address block. One such pictogram is defined herein for use in association with the delivery address block. It may be printed at the same time as the address or pre-printed on an envelope, an insert, or a label, with the address being printed, on the same physical support, at a later stage. The second family covers address block locators which contain an encoded specification of the address block type and location and which can also be used for encoding other data, not directly related to address block location. Such data may include addressee or postal item identifiers, routing data, non-delivery instructions, a return address and references or other data which are relevant for either the mailer or the addressee. It may also include address checking data which may be used to verify correct interpretation of the printed address by the OCR system. In this family, three types of ABL are defined: one based on a pattern of alphanumeric characters; one on a linear bar code and one based on two-dimensional symbologies. These locators can be applied to the delivery address block and to forwarding or return address blocks. They will normally be printed within the same process as the address itself. The Technical Specification is intended to be used by: - mailers, during the production of mail; (....)