How to tell if video is drop frame or

Hi,

Thanks in advance. I am using Encore DVD 2.0 to add closed captions to video. I
have both a drop frame SCC file and a non-drop frame SCC file. How can I tell
which one to use? Can I tell from the way the timecode looks on the timeline? Do
I look at the timeline timecode or the source timecode? For example, in a random
area of video the timeline says 00;02;50;24 while the source says 00:02:50:20.

Thanks! Is there a similar rule for drop frame? I imagine it would be "If
your source timecode and timeline timecode use the same separator (colons or
semicolons) then you've got a drop frame clip." Would that be correct?

And do I then match the type of SCC file I use to the timeline or to the source
file (drop frame vs non-drop frame)?

Drop-frame uses semi-colons, NDF uses colons.

That would not be a correct assumption.