TXT is a DNS record, that contains data in human-readable form for external sources to get info about a certain domain or subdomain. In the most common scenario, such a record is used to prove that you own a domain name in case you're trying to add it to a search engine or to some web traffic analytics platform. Considering that only the domain name owner/administrator may add custom DNS records, the TXT record works as a proof of ownership for the corporation providing the service. Another popular use for this type of records is the e-mail SPF (Sender Policy Framework) security, that makes sure that a particular email address will not be spoofed and that others will not get unsolicited mail from allegedly your mailbox. The TXT record contains information about the mail server where your digital messages come from and functions as proof that it is a trusted one. As there are no standards concerning the content of such a record, you can include any other info also.