Hi José

a) Canonical Pointers
The basic proposal.They look like this example: btc@170.1/179-631-520

A similar/related proposal got posted last month : https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-May/014396.html
The Bech32 encoded transaction position reference allows to solve similar use cases (tx pointers) with a strong error-detection/correction using just 14 chars (encoded state, including error correction / unencoded 40bits).

/jonas