<?xml version="1.0" encoding="utf-8"?>
<PRONOM-Report xmlns="http://pronom.nationalarchives.gov.uk">
  <report_format_detail>
    <FileFormat>
      <FormatID>805</FormatID>
      <FormatName>Icon file format</FormatName>
      <FormatVersion>
      </FormatVersion>
      <FormatAliases>
      </FormatAliases>
      <FormatFamilies>
      </FormatFamilies>
      <FormatTypes>Image (Raster)</FormatTypes>
      <FormatDisclosure>
      </FormatDisclosure>
      <FormatDescription>This is an outline record only, and requires further details, research or authentication to provide information that will enable users to further understand the format and to assess digital preservation risks associated with it if appropriate. If you are able to help by supplying any additional information concerning this entry, please return to the main PRONOM page and select ‘Add an Entry’.</FormatDescription>
      <BinaryFileFormat>Text</BinaryFileFormat>
      <ByteOrders>
      </ByteOrders>
      <ReleaseDate>
      </ReleaseDate>
      <WithdrawnDate>
      </WithdrawnDate>
      <ProvenanceSourceID>1</ProvenanceSourceID>
      <ProvenanceName>Digital Preservation Department / The National Archives</ProvenanceName>
      <ProvenanceSourceDate>02 Feb 2007</ProvenanceSourceDate>
      <ProvenanceDescription>
      </ProvenanceDescription>
      <LastUpdatedDate>11 Nov 2011</LastUpdatedDate>
      <FormatNote>
      </FormatNote>
      <FormatRisk>
      </FormatRisk>
      <TechnicalEnvironment>
      </TechnicalEnvironment>
      <FileFormatIdentifier>
        <Identifier>com.microsoft.ico</Identifier>
        <IdentifierType>Apple Uniform Type Identifier</IdentifierType>
      </FileFormatIdentifier>
      <FileFormatIdentifier>
        <Identifier>image/vnd.microsoft.icon</Identifier>
        <IdentifierType>MIME</IdentifierType>
      </FileFormatIdentifier>
      <FileFormatIdentifier>
        <Identifier>image/x-icon</Identifier>
        <IdentifierType>MIME</IdentifierType>
      </FileFormatIdentifier>
      <FileFormatIdentifier>
        <Identifier>x-fmt/418</Identifier>
        <IdentifierType>PUID</IdentifierType>
      </FileFormatIdentifier>
      <ExternalSignature>
        <ExternalSignatureID>811</ExternalSignatureID>
        <Signature>ico</Signature>
        <SignatureType>File extension</SignatureType>
      </ExternalSignature>
      <InternalSignature>
        <SignatureID>440</SignatureID>
        <SignatureName>Icon file format</SignatureName>
        <SignatureNote>Header: (00000100) followed by number of images used in file. For purposes of this signature, range of limited to 1-9 - the largest number of images that was observed in any Icon file used for testing was 8. Header sequence followed by image directory, then sequence (000028000000{2}0000{2}00000100[01:20]0000000000)</SignatureNote>
        <ByteSequence>
          <ByteSequenceID>554</ByteSequenceID>
          <PositionType>Absolute from BOF</PositionType>
          <Offset>0</Offset>
          <MaxOffset>
          </MaxOffset>
          <IndirectOffsetLocation>
          </IndirectOffsetLocation>
          <IndirectOffsetLength>
          </IndirectOffsetLength>
          <Endianness>
          </Endianness>
          <ByteSequenceValue>00000100[01:09]00{3}00[00:01]00{1}00{3}00*000028000000{2}0000{2}00000100[01:20]0000000000</ByteSequenceValue>
        </ByteSequence>
      </InternalSignature>
    </FileFormat>
    <SearchCriteria>Criteria</SearchCriteria>
  </report_format_detail>
</PRONOM-Report>
