How to change message-citation-line-function

[William Daffer]

  I want to use a specific citation in a certain group. I tried to
  change message-citation-line-function to a function of my own
  creation by doing

    (add-to-list 'gnus-newsgroup-variables 'message-citation-line-function)

  in my .gnus and 

    (message-citation-line-function 'my-citation-line-function)

  in the group parameters for the group in question.

  But message-citation-line-function was always nil, whatever the group.

  Suggestions?

whd
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