.ETH inscription domain extension have nothing to do with Ethereum Name Service (ENS).
The value of these inscriptions is fully speculative, although worth saying there are more than 250,000 .ETH inscription domain names were registered in 2023
There is a project NewCryptoSpace that launched social metaverse based on numeric .ETH inscription domains.
A domain name is the first part of the full domain text, e.g. in hello.eth it's "hello", in google.eth it's "google".
A suffix is the last part, e.g. in hello.eth it's "eth", in google.eth it's "eth"
There are no specific limitations, for the Ethscription indexer a domain has the same treatment as just any other text string.
Full Text is the correct data format for inscription to be considered an inscription by the indexer
Omniscriber shows full text before encrypting it into Hex for full transparency
HEX is an encrypted representation of Full Text
This is the exact way how inscriptions are stored on the blockchain
OmniScriber checks if the full domain string
{name}.{suffix} is already inscribed (registered) on chain.
Although you can technically inscribe duplicate information because blockchain nature is permissionless, indexers will ignore duplicates and the ownership is reserved for the historically first inscriber
Copies current Hex from the HEX field into users clipboard
(Optional) Users can create their inscription without connecting wallet to Omniscriber by pasting HEX into "Hex data" field in the wallet "Send" form
Omniscriber creates a transaction with the current text from the Full text field (encrypted as a Hex)
After transaction is broadcasted in the blockchain the user becomes the owner of this domain name