Canonical Transaction Ordering - CTOR for short - is a rule on Bitcoin Cash (BCH) which requires transactions within each block to be ordered by their transactions IDs.
This ordering enforcement and consistency allows for enhanced compression techniques, and faster/simpler transaction inclusion/exclusion lookups. This is one improvement of many which aim to enable Bitcoin Cash (BCH) to be a worldwide currency.
CTOR was enabled on Bitcoin Cash (BCH) during the scheduled November 2018 hardfork.
* All terms and definitions may update as the Cryptionary improves.