Definitions of recognise:

• verb:   detect with the senses
• verb:   show approval or appreciation of
• verb:   perceive to be the same
• verb:   be fully aware or cognizant of
• verb:   grant credentials to
• verb:   accept (someone) to be what is claimed or accept his power and authority
• verb:   express obligation, thanks, or gratitude for
• verb:   express greetings upon meeting someone