Just to be clear;  it is permissible to switch out of Nemeth, enter a UEB symbol, and switch back into Nemeth when the referenced material is mathematical.?.  Nemeth Code 2022 lists Nemeth references in Rule 9.  I have used those symbols when inside switches.  The ones that are confusing me are the section sign and the double vertical bar for which there are no Nemeth reference symbols.  I have devised a symbol for those and maintained the Nemeth thread as this is my understanding of keeping the reference symbol inside the switches when referenced material in the body of the table is mathematical…. am I wrong?

I think what is confusing me is when Rule 9 says Unified English Braille symbols must not be used.