When registering a domain, the information contained for the registrant and contacts is stored and transmitted to the registry that oversees the TLD you’ve just purchased. This information is then made available in whois searches. When whois privacy is purchased, it will mask your contact information at the registry level so that only you, the registry, and us being able to see the true contact information for the domain.
The availability of whois privacy is determined by the registry. Most domain types support this.
.ca Specific Rules
.ca domains are handled slightly differently. Please see the blog article which talks more about this. In essence, CIRA uses the Canadian Presence Requirement category to either automatically hide (for individuals) or to automatically show your contact information for businesses.
