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ICC Signature Registry


The ICC Profile Format Specification details many basic data types that are found in an ICC profile. One of these data types is a signature -- a 32-bit value used as an identification code. There are many types of signatures specified in the ICC profile format specification. Some of these are required to be registered by the ICC, others are optional. However, by registering them it ensures there is no conflict caused by different vendors using the same signature. Vendors who use signatures that have not been registered run the risk that their profiles may be misinterpreted.

Profile creators and/or device manufacturers choose the values they wish to register, and their associated meanings, for the signatures registered. Through this system they can see if any desired signatures are still available for registration. If so, they can then request that the ICC assign that signature to their company.

All ICC signatures have four ASCII characters and their 32-bit hex equivalent. They are grouped into the following registries:

Manufacturer registry

Device registry

Private and ICC tag and CMM registry

iccMAX signature registry

The Manufacturer and Device registries enable vendors to register their company and their specific device(s). The Private and ICC Tag and CMM registry contains the signatures of both public and private tags and tag types, and of CMMs. This ensures there is no conflict between private and public tags, or between private tags. The iccMAX registry includes all the signatures in the new iccMAX specification, grouped into different categories.

Registering your signatures

To register a signature first view the appropriate registry to ensure the signature you wish to register is available. To register a device model signature with the ICC, you must first have a manufacturer signature. To register manufacturer and device signatures device you can follow the instructions for registration via the registry page.

To check for availability of CMMs, private tag, or tag type signatures, see the Private and ICC Tag and CMM Registry. This now includes iccMAX tag and type signatures.

To register a private tag, tag type or CMM send the details (company name, the hex and ASCII values of the signature, whether it is a CMM, tag or tag type, and whether it is for use with ICC.1 or with iccMAX) to the ICC Technical Secretary.

Private tags are not documented by ICC. A vendor can optionally provide documentation of a private tag, either through a document hosted on the ICC site or through a link to a URL on the vendor's site. Please contact the ICC Technical Secretary for details.

For private tags holding metadata, vendors are recommended to check later versions of the ICC specification to see if the requirements of the proposed tag are met be an existing tag definition. For example, if an iccMAX metadata tag is used in a v4 profile it will avoid the need to define a new tag that duplicates an existing well-defined tag. Such a tag will normally be treated by a CMM as a private tag.