From BrahmaKumaris.Info Encyclopedia
Avyakt BapDada is "Bap" or Shiv Baba believed to be God, combined with "Dada Lekhraj", now called Brahma Baba, in a subtle or "avyakt" angelic form,
The spoken words of BapDada since 1969 are known as Avyakt Murlis. They are spoken, or channelled in Madhuban through the medium of Dadi Gulzar and are published by the BKWSU.
For a collection of Avyakt Murlis and summaries of Avyakt Murlis, see; http://www.brahmakumaris.info/indexam.html