How did the members of the Pre-Raphaelite Brotherhood sign their paintings?

The members of the secret brotherhood formed in 1848 exhibited their paintings anonymously with the signature PRB.

The founding members were Dante Gabriel Rossetti, William Holman Hunt, and John Everett Millais, who were rebelling against the unimaginative academic art of their day.

Though the PRB (unmasked in 1850) had a profound influence on Western painting, it lasted as an organization for only about 10 years.