The height from the top line to the baseline on the tracing rows. Bigger lines are for younger hands.
Only turn this on if you chose bleed in KDP. The page is then 0.125" wider and 0.25" taller, as KDP asks.
Ten more pages after Z, one for each digit, with start dots and arrows like the letters.
Sight words, names, a theme. Separate them with commas or new lines. Each gets a page after Z: the word large with start dots and arrows, then rows to trace. Letters and numbers only, up to 52 words (42 with Numbers 0–9 on).