HTTP::respond Command in the CLIENTSSL_HANDSHAKE Event

Hi all,

I'm trying to use this

HTTP::respond 302 Location "http://google.co.uk/"

under the CLIENTSSL_HANDSHAKE event but keep getting this error;

 - Illegal argument. Can't execute in the current context. (line 11) invoked from within "HTTP::respond 302 Location "http://google.co.uk/""

I'm running VE, v11.3.0 Build 3138.0. No other rules are applied to the Virtual Server. I'm not using any other ::respond or ::redirect commands anywhere within what is probably a 150 line or so irule also using the AUTH_RESULT and CLIENT_ACCEPTED events.

The wiki doesn't list CLIENTSSL_HANDSHAKE as a valid event for the HTTP::respond command but this article suggests it's allowed from v10.1: https://devcentral.f5.com/wiki/iRules.Client-Cert-Request-by-URI-with-OCSP-Checking-v10-1.ashx.

Any help gratefully appreciated. Thanks.