LTM policy to x forward the cipher suite used for TLS

We currently have a policy that will send the TLS version that is negotiated on a TLS connection to the back end server for logging via X Forward For.  We would like add what cipher suite is being used so we can report on any weak ciphers being used.

To send the TLS version we use:

tcl:[SSL::cipher version] in the policy and it logs within IIS as a customer log entry.

I have searched for the valid tcl SSL options are but haven't had much luck.

Any assistance/help would be appreciated.

Thanks,

Joe