A new chain letter has hit the tipping point on Facebook in recent days called “25 Random Things About Me.” It’s one of the largest cases of chain letters being forwarded through Facebook using Facebook Notes we’ve seen to date.

While Facebook can’t pinpoint exactly when the chain started, a Facebook spokesperson told Inside Facebook that:

The number of total Facebook Notes created per day has increased over 100% in the last week

The number of people tagged in Facebook Notes per day has increased 5x in the last week

Here’s how the chain letter works: the above instructions, which accompany the 25 things being shared, ask recipients to write up their own “25 Random Things About Me” Note and “tag” 25 of their Facebook friends in it.

While chain letters have been around since at least the 19th century, the use of Facebook Notes as a channel for one-to-many forwarding is still relatively uncommon compared to popular content sharing Facebook applications and even email.

However, as with any new communication tool, the social rules around Facebook Note tagging are still being defined: