D&D 5e (2024)

Source: Arcana Unleashed

Wondrous Item, Common

This item functions as a sheet of Parchment. After writing on it, you can take a Magic action to fold or roll the sheet and seal it while speaking or signing a word or short phrase. If a creature unseals the sheet without using the same word or phrase, the writing on the sheet appears as if it were written in an unknown and unintelligible script.