`banlist.dat` was introduced in https://github.com/bitcoin/bitcoin/pull/6310, storing nodes that were automatically banned (due to exceeding the misbehavior threshold) and manually banned (through the `setban` RPC).

Automatic bans were removed in https://github.com/bitcoin/bitcoin/pull/19219 and replaced with a discouragement filter. That filter is not saved to disk/persisted over shutdown/startup. The `banlist.dat` therefore now only contains addresses that have been banned through the `setban` rpc.

Since https://github.com/bitcoin/bitcoin/pull/15935, we have a specific file for configuration that is updated through the RPC and persisted over shutdown/startup, namely `settings.json`. We should therefore move the manual ban configuration from `banlist.dat` to `settings.json`. Doing so has a couple of benefits:

- `settings.json` is human readable and easily analyzable by any json parser.
- we wouldn't need to maintain custom [de]serialization code for the `banlist.dat` file.

`banlist.dat` is expected to be fairly small and infrequently updated, so disk space/performance are not huge concerns.
}
#ifndef WIN32
    if (!args.GetBoolArg("-sysperms", false)) {
        umask(077);
    }
    
    registerSignalHandler(SIGTERM, HandleSIGTERM);
    registerSignalHandler(SIGINT, HandleSIGTERM);
    
    registerSignalHandler(SIGHUP, HandleSIGHUP);
    
    signal(SIGPIPE, SIG_IGN);
#else
    SetConsoleCtrlHandler(consoleCtrlHandler, true);
#endif
    std::set_new_handler(new_handler_terminate);
    return true;
}
bool AppInitParameterInteraction(const ArgsManager& args)
{
    const CChainParams& chainparams = Params();
    
    
    
    
    
    std::string network = args.GetChainName();
    if (network == CBaseChainParams::SIGNET) {
        LogPrintf("Signet derived magic (message start): %s\n", HexStr(chainparams.MessageStart()));
    }