Marking Playing Cards of Suits

It's known to all that in one poker deck there are 52 playing cards + 2 jokers. The 52 cards divide into 4 groups, each one includes the number 1 to 10 and J Q K.

Just as that in the face, the marking playing cards can get the invisible marks of numbers and suits on the back so that you can easily recognize it with infrared contact lenses.

People all know that these are four suits for the poker cards, but seldom know the meaning the suits, spade, heart, club and diamond.

People of different countries have given different cultural interpretations of the four suits with their national culture. There are several sayings of other countries online.

In some Chinese area, the four suits of poker deck may means 4 children of a big family where the poker joker are the parents, two sons spade and club, and two daughters heart and diamond. The spade is older than the heart, then the club, and the diamond is the youngest one. And the four brothers and sisters always work together and help each other. It's a nice saying and also people's wish for a kind family.
The suits represent the four main industries of the society at that time, in which spades represent spears and symbolize military personnel, plums represent three-leaf flowers, symbolizing agriculture; squares represent bricks used by artisans; and peaches represent red hearts, symbolizing pastors.
Another saying goes that these four suits are derived from the ancient European tarot card divination, in which the spades represent the sword and symbolize justice, the plums represent the scepter, symbolizing power, the squares represent coins, symbolizing wealth, and the peaches represent the holy grail, Symbolizes romantic love.