[Enigmail] Subkey revocation certificate

[ushills]

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As I have created a separate signing sub key (see separate post about
issues with this) how do I go about just creating a revocation
certificate for the sub-key and not my primary key.
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iD8DBQFJjBRJ99A+Y8omXcYRAme2AJ0ZLDhMjRptuwfSRCsb8E0LCMzHuQCeM/Ni
zB0TBmAr282DXm+qYK/quGU=
=kBpj
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