[Cyykratahk]

Yes, here are the reserved TLDs [0]:

    test
    example
    invalid
    localhost
    local
    localdomain
    domain
    lan
    home
    host
    corp

0. https://www.ietf.org/archive/id/draft-chapin-rfc2606bis-00.h...

[Karunamon]

Be careful, that is a decade plus old expired draft of a proposed update to RFC 2606. The current version of the standard, including 6761 which updates it, does not reserve most of those.

https://datatracker.ietf.org/doc/html/rfc2606#page-2 https://datatracker.ietf.org/doc/html/rfc6761

You are probably safe using names like .lan and .corp but they are not currently protected by standard in the way example is.

[Cyykratahk]

Ah, that's a good point.