The note to robert is received during the Ritual of the Mahjarrat quest. The note was written by Robert the Strong, and is addressed to himself. It contains information about the code to Kethsi (which is in Bob's collar) as well as some random information to prove to Robert that he wrote the note.
Presumably, the note will have a use at some future time. Until then, for players wishing to save Bank space, the note can be destroyed, as it can be reobtained in Kethsi. Mod Raven has stated the note is something for future content and "at some point all will be revealed".
I know none of this makes sense to you now, but I have seen the alternative, and this information is very important and should not be forgotten, not idly revealed.
The code to what you seek is DIRAKS.
You must preserve the secret at all costs and make sure only the right people learn it. This will not be the only time the enemy will rise. The stonetoucher must also know what to do. The Temple Knights will be at the start of the stonetoucher's trial.
The animal is a cat.
The time is plus 2139.
Put the key to the secrets on your collar.
Good luck.-Robert the Strong.