When defining condtion in AccoMASTERDATA / Settings / Conditions / Condition field, I can enter whatever combination I want

[Field] == "T-M"

[Field]== "T*M"

[Field] == "T#M"

...

but as soon as i try to write or copy&paste [Field] == "T&M", borders of condition field turns red and don't allow me to use "&" character.