The advice and guidance we get seems utterly random at times.
Take my most recent prescription. The 25 microgram tablet has to be taken in the morning, 30 minutes before breakfast, caffeine-containing drinks or other medicines. But no such instructions about the 100 microgram tablet! I can only assume that the instructions are, in fact, arbitrary.
(Also, the 25 microgram tablets are prescribed to make my dose up to 112.5. But the instructions say to take one a day. Someone needs to brush up on their logic and arithmetic.)