The square with the red slash does not set transparency. You can change the color of the text to match the color of the background, which make the texts appear invisible.
Unless the background is not a solid color....
Thanks though, I think I figured out how to make the text disappear by changing the size to 500 points when a condition is met....it doesn't fit in the field, and disappears.
What does the white square with the red slash do if it is not intended to set transparency? That is what it does when used to specify the fill of a field.
I'm facing essentially the same problem, but I am trying to make a text label (not a field) disappear when certain conditions are met.
Furthermore, the text is positioned in a portal which is set to have the alternating rows shaded in light gray.
If I set the conditional formatting on the text to white (or "transparent", since they appear to do the same thing), it disappears properly in the white portal rows, but is still visible in white in the gray portal rows.
Personally, I feel that this is a bug.