PSET: docs: Mark PSBT_ELEMENTS_GLOBAL_TX_MODIFIABLE bit 0 as reserved/unused
PSET: docs: Mark PSBT_ELEMENTS_GLOBAL_TX_MODIFIABLE bit 0 as reserved/unused

Elements does not set or process this bit or this field currently.

ElementsProject/elements,ElementsProject/elements,ElementsProject/elements,ElementsProject/elements,ElementsProject/elements,ElementsProject/elements