SPF, DMARC, verification tokens and several email-related mechanisms publish data through DNS TXT records.
TXT is a container. The meaning comes from the protocol querying a particular DNS name and interpreting the returned text.
Do not merge unrelated protocols
An SPF policy at a domain and a verification token at the same name are separate TXT records. A DMARC policy belongs under _dmarc. DKIM public keys normally live under a selector-specific _domainkey name.
DNS interfaces can display long TXT data as multiple quoted character strings. DNS software concatenates the character strings within a single TXT resource record for protocol use.