In my question Why can I only vote 37 times?, Joseph Wright answered that there is a rule saying that I can only upvote 30 answers per day.
Looking in the FAQ I found a short explanation (with the first look I oversee this):
A maximum of 40 votes can be cast per user per day, however, to reach the maximum you must vote on at least 10 questions.
I found no place where I can see how many answers I upvoted today and how many questions. Even not in the summary profile, which only shows the complete voting per day (answers and questions together).
Because this rule is important I suggest to display somewhere on the page the actual status of upvoted questions and answers per day separately. That could be, for example, in the summary profile for the votings or near user name or received bagdes in the headline.