U2 fans received a strange surprise in their mailbox this week. The GRAMMY-winning band surprised fans with a blackout letter containing a vague message, possibly teasing an upcoming release.

The message that emerges beneath the shadowed image of two people holding hands reads, "Blackout it's clear who you are will appear," followed by "U2.com."

The bottom of the letter reads, "U2 will announce __________ on __________," with black bars covering the details. As of the time of this writing, the band's website has yet to make mention of the announcement referenced in the mailing.

However, the mailings do reveal one thing about U2: they continue to have excellent taste in poetry. The letters are printed on text referencing William Blake's late 18th century illustrated poetry collection "Songs Of Innocence And Of Experience," the same collection that inspired the title of the band's 2014 album, Songs of Innocence. More recently, modern author/poet Austin Kleon has helped popularize this blackout style of poetry used in the mailings.

U2 just wrapped a European tour run and will head out for more shows across the U.S. and South America this fall.

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