Unity UI Custom font properties - what do they do?

Some of them I've figure out, others are a mystery:

• Line Spacing - space (in pixels) between lines of text - fine
• Tracking - seems to be the space added after a character, but as a percentage of its width, which doesn't make it all that useful to me, since the space after an "I" will be minimal while the space after a "W" will be huge, making the line look weird
• Character Spacing - no idea what this does, since it seems to have no effect, regardless of what number I put in here
• Character Padding - not really sure what this does either, when it is set to 1 or higher, my font looks correct ( ), when it is set to 0, the font looks out of proportion ( )
• Convert Case - lowercase translated to uppercase characters - fine
• Font Rendering Mode - no idea what this is used for either

Anyone fully understand these properties? I can't seem to find any good documentation.