=?utf-8?Q?=E2=97=8C_?=in LB28a in UAX14 of Unicode 15.1.0

[Daniel Bünzli]

Hello, 

I can’t figure out what the ◌ character classification represents in:

  https://www.unicode.org/reports/tr14/proposed.html#LB28a

Any hint ? 

Best,

Daniel