Is it mandatory that we include our parents' names in our wedding invitations?

My fiance and I are funding our wedding. The invitation cards we have designed is very personal as only people close to us are attending. Only about 100 people. The invitation do not mention the names of our parents. We heard that to get visa for our honeymoon to Singapore, we need to have our parents' name on the cards. But I feel it will jar with the informal nature of our cards. Is it really necessary to include our parents' names?