Marc,
Where in the manual is this broken down?
It isn't. The new manual has not been written yet.
ie: pho {filenamebase:-3} means the text will replace the first 3 letters.
Well not exactly. The {filenamebase:-3} extracts the last three characters of the filename. So we're building a new name comprising the letters "pho " and the last three characters of the current filename.
For instance: How do you remove the first 3 digits and the last 3 (before the suffix).
That's harder to do if your filenames are variable length. But basically you do something like this:
{filenamebase:3,5}
...which would extract five characters, starting with the fourth character. You'll need to know how long each filename is and adjust accordingly.
How do you delete the first 3 letters?
It's more like how do you keep everything but the first three letters?
{filenamebase:3}
(extracts from the fourth character to the end of the string.)
How do you have it recognize spaces?
I'm not sure what you're asking. To the substring extraction feature, a space is just like any other character. What is it that you're trying to accomplish?
-Kirk