U+A81B Syloti Nagri Letter Bo

The Wikipedia has the following information about this codepoint:

Sylheti Nagri or Sylheti Nāgarī (Sylheti: ꠍꠤꠟꠐꠤ ꠘꠣꠉꠞꠤ, ISO: Silôṭi Nagri, pronounced [silɔʈi nagɾi]), known in classical manuscripts as Sylhet Nagri (ꠍꠤꠟꠦꠐ ꠘꠣꠉꠞꠤ, Sileṭ Nagri) as well as by many other names, is an Indic script of the Brahmic family. The script was historically used in areas of Bengal and Assam that were east of the Padma, primarily in the eastern part of the Sylhet region, to document Muslim religious poetry known as puthis; having no presence in formal documentations. In the course of the 20th century, it has lost much ground to the standardised Eastern Nagari script. Printing presses for Sylheti Nagri existed as late as into the 1970s, and in the 2000s, a Unicode font was created for the script.