It was explained to me that I could cut out letters on a black layer so I could reveal what's behind it. In my case I wish to overlay this on a track of video. Here were the instructions:
Create a new file with a black background
Add a new layer
Select the horiz mask text tool and type the text where you want it
Press the delete button
Pressing the Delete button deletes everything instead of what's inside of the 'craweling ants'.
Create a new image using the 720x534 Std. NTSC DV/DVD preset.
Unlock the created layer by double-click and rename to Layer 0.
Right click on the "T" tool to select the horizontal mask tool.
Click on the black layer and a red mask will cover the layer with the type cursor blinking
Type the desired text.
Then click on the magic wand button which will get one out of the horizontal mask mode leaving just the black background with 'marching ants' around the text.
Hit the Backspace key - which works like the 'delete' key. This will delete the black within the type.