Unsupported method 'PROPFIND' ?

From: TimeNet <squid@dont-contact.us>
Date: Thu, 13 May 1999 14:59:57 +0800

I found there are lots "Unsupported method 'PROPFIND'" in cache.log.
(2.2.STABLE2)

1999/05/13 14:54:13| parseHttpRequest: Unsupported method 'PROPFIND'
1999/05/13 14:54:13| clientReadRequest: FD 40 Invalid Request
1999/05/13 14:55:16| parseHttpRequest: Unsupported method 'PROPFIND'
1999/05/13 14:55:16| clientReadRequest: FD 27 Invalid Request
1999/05/13 14:56:18| parseHttpRequest: Unsupported method 'PROPFIND'
1999/05/13 14:56:18| clientReadRequest: FD 62 Invalid Request
1999/05/13 14:57:20| parseHttpRequest: Unsupported method 'PROPFIND'
1999/05/13 14:57:20| clientReadRequest: FD 29 Invalid Request
1999/05/13 14:58:22| parseHttpRequest: Unsupported method 'PROPFIND'
1999/05/13 14:58:22| clientReadRequest: FD 48 Invalid Request

what can I do for this error?
Received on Thu May 13 1999 - 00:56:40 MDT

This archive was generated by hypermail pre-2.1.9 : Tue Dec 09 2003 - 16:46:16 MST