Illusory Script
Casting Time
Range
Target
A piece of paper or other writing material
Components:
ink worth at least 10 gold, consumed by the spell
Duration:
10 days
You inscribe a message onto the target and wrap it in illusion until the spell ends. You and any creatures that you designate when the spell is cast perceive the message as normal. You may choose to have other creatures view the message as writing in an unknown or unintelligible magical script or a different message. If you choose to create another message, you can change the handwriting and the language that the message is written in, though you must know the language in question.
If the spell is dispelled, both the message and its illusory mask disappear.
The true message can be perceived by any creature with truesight.
Source