UITK: Okay to modify WEB-INF files under httpd?

pbenn

TS 6.5 SP1 Sol 9

I'm customising the Advanced search screen and KB 54261 recommends a fairly inocuous sounding edit to the search.xml file (in /httpd/webapps/content_center/WEB-INF/conf/search) that I want to use to modify the Content Type drop down. The trouble is, the uicg.650a.cg.pdf document says quite explicitly:

Once the web application is installed, these toolkits, along with other internal toolkits
corresponding to subsystems (such as VisualPreview) without online help or custom style
sheets, will appear in the deployed web application under iw-home/httpd/webapps/
content_center.
Do not modify any files in the merged and deployed web application in this location. Any
modifications made to these files are not only unsupported but will also be overwritten the
next time the web application is rebuilt.

In light of this, is it okay to edit the WEB-INF files, or not?

Thanks,

P.