What does H stand for?

What does H mean?

H	Horse Miscellaneous » Farming
H	Horshank Miscellaneous » Unclassified
H	Horshankjesus Miscellaneous » Unclassified
H	Horus Miscellaneous » Unclassified
H	Hospital Governmental » Transportation
H	Hospitalization Medical » Hospitals
H	Hot Academic & Science » Physics
H	Hot Governmental » NASA
H	Hotmail Miscellaneous » Unclassified
H	Hour Miscellaneous » Unit Measures
H	Hours Governmental » NASA
H	How Miscellaneous » Unclassified
H	Howard Miscellaneous » Names and Nicknames
H	Hub Computing » Networking
H	Hucking Miscellaneous » Unclassified
H	Hue Miscellaneous » Colors
H	Huggable Internet » Chat
H	Huh? Internet » Chat
H	Humanities Academic & Science » Universities
H	Humility Community » Religion
H	Humor Miscellaneous » Unclassified
H	Hundreds Miscellaneous » Unclassified
H	Hundredths Miscellaneous » Unclassified
H	Husband Community » Housing
H	Hybrid Academic & Science » Electronics