DICOM PS3.18 2020e - Web Services

8.8.5 Selected Character Set

The origin server shall determine the Selected Character Set(s) as follows:

  1. Select the first supported character set in the "charset" parameter(s) of the Selected Media Type.

  2. Otherwise, select the highest priority supported charset in the character-set Query Parameter.

  3. Otherwise, select the highest priority supported charset in the Accept-Charset header field.

  4. Otherwise, if the Selected Media Type has a default character set that is supported, select it.

  5. Otherwise, select UTF-8.

Rendered representations returned in the response shall have all contained strings returned in the Selected Character Sets.

If the character set in which the Target Resource is encoded is not the Selected CharacterSet:


This means that some Instances may be convertible, and others will not be, even though they have the same Specific Character Set (0008,0005).

If the user agent chooses to perform its own conversion rather than have it done by the origin server:

  1. The user agent may omit the Accept-Charset header field or send the"*"wildcard

  2. The user agent may transcode the character set replacing all unknown characters with a suitable replacement. For example:

    • A question mark ("?"), or other similar character indicating an unknown character.

    • The corresponding Unicode Code Point for the character, represented as "U+xxxx".

    • The four characters "\nnn", where "nnn" is the 3-digit octal representation of each byte (see Section “Encoding of Character Repertoires” in PS3.5).

DICOM PS3.18 2020e - Web Services