Duerkopp Adler 550-867 Service Instructions Manual page 85

"Bobbins"
When this function is activated all registered bobbins will be
displayed. By pressing the "Delete" button preselected bobbins can
be deleted.
–
Press the bobbin that is to be deleted.
–
Press "Delete".
A confirmation request will appear:
–
Press "OK".
The bobbins will be deleted.
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