EIP 1167 sets a standar for minimal proxy contracts
The exact bytecode of the standard clone contract is this: 363d3d373d3d3d363d73bebebebebebebebebebebebebebebebebebebebe5af43d82803e903d91602b57fd5bf3 wherein the bytes at indices 10 - 29 (inclusive, meaning bebebebebebebebebebebebebebebebebebebebe) are replaced with the 20 byte address of the master functionality contract.
We want the explorer to automatically identify and verify them, and indicate that they are a proxys and link them to the functionality contract used, so users can easily see the ABI and code of the functionality contract that they should use to interact with the proxy contract.