Avoid ambiguity in wildcard blocking

I've been using wildcard blocking for some time now, since it was always possible by following these guidelines. So I've been adding domains to 03-pihole-wildcard.conf manually, these are my entries:
address=/.ligatus.com/192.168.2.250
address=/.gigya.com/192.168.2.250
address=/.trackuity.com/192.168.2.250
address=/.bannerflow.com/192.168.2.250
address=/.doubleclick.net/192.168.2.250
address=/.clicksgear.com/192.168.2.250
address=/.telemetry.microsoft.com/192.168.2.250
Notice the leading period! When you add facebook.com (example), the domain thisismyfacebook.com will also be blocked e.g. ambiguity. You can prevent this by adding the leading period.
I've been running it like this, using my rules, the site www.trackuity.com is blocked, in v2.12 even with a status pi-holed (wildcard).
The webinterface already shows my entries correct (e.g. with a leading period)
Unfortunately, the webinterface doesn't allow a leading period, so may I suggest you always add the leading period when the script adds it to 03-pihole-wildcard.conf.

No! That is impossible. dnsmasq eliminates any leading . when loading the domains from the config files.

		char *domain = NULL;
		/* elide leading dots - they are implied in the search algorithm */
		while (*arg == '.') arg++;
		/* # matches everything and becomes a zero length domain string */
		if (strcmp(arg, "#") == 0)
		  domain = "";

Thank you for this clear explanation. I was mislead by the article of PromoFaux, stating:
Create the file /etc/dnsmasq.d/02-wildcards.conf, and add in your *.domain.com etc there in this format:
address=/.test.com/xxx.xxx.xxx.xxx
Where xxx.xxx.xxx.xxx is your Pi-hole's IP.
This will block all access to *.domain.com.
Maybe you could ask him to update the article.

Maybe you could ask him to update the article.

You can talk directly to me, it's OK I don't bite! :smiley:

Updated.

And this corroborates @DL6ER's explanation.