For a handshake to qualify:

• Donald Trump and Xi Jinping must participate in the same handshake simultaneously (for two people, this is a standard handshake; for three or more people, all must have physical hand contact at the same moment)
• The handshake must involve direct hand-to-hand contact between the individuals
• Duration is measured from the moment all specified individuals' hands make initial contact until the moment any individual breaks contact
• The handshake must be voluntary and intentional (not accidental contact)
• The handshake must occur in person (not virtual or simulated)
• Gloves, mittens, or other hand coverings are permitted
• If individuals shake hands multiple times, only the first instance counts

For duration measurement: if only photographic evidence exists showing a handshake occurred but duration cannot be determined, the market resolves to No for all duration-specific strikes.