How to add a verify code in head?

I tried to add a code like

PHP Code:

<!-- verifi site 123456 --> 


into headinclude template, but this is not shown. Maybe I have to add it through vbseo?

Thanks for support

vBSEO will strip HTML comments from the output if the HTML Cleanup option is enabled in the vBSEO-CP.

vBSEOCP -> Other Enhancements -> Cleanup HTML Code : Yes / No.

Turn it off and try again.

Although I don't think you should turn off this option just to have a site verified.
Look for alternative means of verification too.

perfect, now works, thanks.

Is the only verify mode accepted by tradedoubler. I think that now I verified it I can turn it on again

i recommend the blank file option. it's less bloat on every page.

you should use the file that the search engines give you instead of adding the code

Is there any way to whitelist an specific part of code? For example, the Google Adsense targeting uses commented code and doesn't get wiped out when activating the cleanup. I need to whitelist my Nielsen//NetRatings code without turning cleanup off.

Thanks.

Currently there is option for that.