New to Shorthand: Intro & ?

Hi Everyone,
I've just started learning Gregg Shorthand--on my own of course because that seems to be the only way to learn now.  I've been practicing a bit with the Anniversary (?) edition that is online. The Unit 2 Dictation Trascription exercise begins with the name Henry Hale.  Both first name and last name contain double hash marks under the middle of the words.  What do they mean?  No explanation in the text so far.  TIA for any help.
Learning shorthand has been an interesting mental challenge.  I began hoping that it would help me in taking meeting minutes and writing short notes of telephone conversations, but have learned that it will take quite a while to learn it well enough to use for such lengthy notes.  The idea of learning another dying art (along with knitting and soapmaking ) was intriguing also.  Being able to write notes that few other living people (at least where I work) can read is just an added benefit .
Tera in Mn

(by tsecker for everyone)