Warrant Officers possess military occupational specialties (MOS) in many basic branches. These branch schools (MOS proponents).
Within a branch there are multiple specialties. For example, there are two specialties within the Adjutant General Branch, Personnel Officer and Bandmaster.

Adjutant General
Fort Jackson, South Carolina
|

AirDefense Artillery
Fort Bliss, Texas |

Aviation
Fort Rucker, Alabama |

Engineer
Fort Leonard Wood, Missouri |

Field Artillery
Fort Sill, Oklahoma
|

Judge Advocate General
Charlottesville, Virginia
|

Medical Service
Fort Sam Houston, Texas
|

Military Intelligence
Fort Huachuca, Arizona |

Military Police
Fort Leonard Wood, Missouri |

Ordnance
Aberdeen Proving Grounds, Maryland
and Redstone Arsenal, Alabama |

Quartermaster
Fort Lee, Virginia
|

Signal
Fort Gordon, Georgia |

Special Forces
Fort Bragg, North Carolina |

Transportation
Fort Eustis, Virginia |

Veterinary
Fort Sam Houston, Texas |