Problem

Outputs with the script OP_TRUE (0x51) are technically "anyone can spend" — any node on the network could claim them by providing an empty scriptSig. In practice, miners or relay nodes would sweep such outputs immediately if they were large and freshly created.

However, if such an output has remained unspent for more than 3 years, it is reasonable to conclude that the value is practically inaccessible — either because the output is too small to justify the fee, or because the original creator intentionally locked funds this way knowing they would not be claimed.

Detection

if (ctx.script_hex === '51') {
  const threeYearsAgo = new Date();
  threeYearsAgo.setFullYear(threeYearsAgo.getFullYear() - 3);
  if (ctx.block_timestamp < threeYearsAgo) return '013';
}

Classification

Loss bucket: 2 (Probably Lost). Included in "Probably Lost" slider stop.

Note: Fresh OP_TRUE outputs (< 3 years) are classified as loss_bucket=0 until they age into the threshold. The snapshot updater periodically re-evaluates dormancy.