| The Call-Info header field provides additional information about the
caller or callee, depending on whether it is found in a request or
response. The purpose of the URI is described by the "purpose"
parameter. The "icon" purpose designates an image suitable as an
iconic representation of the caller or callee. The "info" purpose
describes the caller or callee in general, for example, through a web
page. The "card" purpose provides a business card, for example, in
vCard or LDIF formats.
Use of the Call-Info header field can pose a security risk. If a
callee fetches the URIs provided by a malicious caller, the callee
may be at risk for displaying inappropriate or offensive content,
dangerous or illegal content, and so on. Therefore, it is
RECOMMENDED that a User Agent only render the information in the Call-Info
header field if it can verify the authenticity of the element that
originated the header field and trusts that element. This need not
be the peer User Agent; a proxy can insert this header field into requests.
For Example:
Call-Info: http://jcp.org/duke/photo.jpg;
purpose=icon, http://jcp.org/duke/; purpose=info
author:
BEA Systems, NIST
version:
1.2 |