Holding pattern shape and terminology
Unless the clearance given by ATC (or the route documentation contains instructions to the contrary), all turns after initial entry into the holding pattern shall be made to the right.
Countries applying US regulations use the phrase ’standard pattern’ for a right-hand pattern, and ’non-standard pattern’ for a left-hand pattern.
Source: ICAO
See also:
Approaching Holding fix
Entry into the Holding
Holding pattern shape and terminology
Standard limitations for Speed, Rate of turn and Timing (Holding)
Flying the Holding pattern – Wind correction
Leaving the Holding pattern
Protected airspace (Holding)