tags 851357 wontfix thanks Upstream does not intend to change this behavior. See the thread starting at http://mail-archives.apache.org/mod_mbox/httpd-dev/201702.mbox/ %3C20170202125319.GA15948%40redhat.com%3E I won't deviate from upstream in the Debian 9 squeeze release, but I will allow underscores in the upcoming DSA for jessie. People who need underscores will have to resort to 'HTTPProtocolOptions unsafe'.