Notes are used for writing information and can be created anywhere without limit, although excessive use, so called note spamming is strongly discouraged. They can also be put inside an envelope for better organization. More information on using notes and envelopes is found on the inventory page.
Notes are either editable or non-editable. Non-editable notes are permanent in the game, and will remain forever, while an editable note vanishes if both the title and text body is of zero length.
Notes have a capacity of 65535 characters, so watch out if you write long notes.
Notes are not objects per se and does not have a weight.
You can write some HTML tags in notes, to format the text of them. JavaScrip has been disabled.
As per March 2015 there was more than 500.000 notes in the game.