Susan,

Thank you for asking. Please let me direct you to the following locations in the GTM –  Guidelines for Technical Material (PDF) – for information “direct from the horse’s mouth” about the signs you brought up.

• The “bar over” and “simple right-pointing arrow over” are given in the list at the beginning of GTM section 12
  • ⠱ (dots 156)
  • ⠘⠱ (dots 45, 156)
• The “horizontal birectional arrow” is on page 63 of the GTM in section 13. Information about the “directly above indicator” is discussed in GTM section 7.9
  • ⠳⠺⠗⠕ (dots 1256, 2456, 1235, 135)
  •  ⠨⠔ (dots 46, 35)
• The “angle sign” is in the list at the beginning of GTM section 11
  • ⠸⠪ (dots 456, 246)

Attached is a document with transcriptions of specific sections from your sample print page.

Cheers!
–Kyle