RH, Rh, rH, or rh may refer to:
Companies
*
Red Hat
Red Hat, Inc. is an American software company that provides open source software products to enterprises. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina, with other offices worldwide.
Red Hat has become ass ...
, an American software company
*
Republic Express Airlines (IATA designator), a cargo airline in Indonesia
*
RH (company), an American furniture chain formerly known as Restoration Hardware
Science and technology
*
Relative humidity, the ratio of the partial pressure of water vapor to the equilibrium vapor pressure of water at a given temperature
*
Releasing hormone
Releasing hormones and inhibiting hormones are hormones whose main purpose is to control the release of other hormones, either by stimulating or inhibiting their release. They are also called liberins () and statins () (respectively), or releasing ...
*
Rh blood group system
The Rh blood group system is a human blood group system. It contains proteins on the surface of red blood cells. After the ABO blood group system, it is the most likely to be involved in transfusion reactions. The Rh blood group system consists ...
(''Rhesus factor''), a classification to describe blood types in humans
*
Rhodium, symbol Rh, a chemical element
* R
H, the
Rydberg constant for hydrogen
*
Riemann hypothesis
In mathematics, the Riemann hypothesis is the conjecture that the Riemann zeta function has its zeros only at the negative even integers and complex numbers with real part . Many consider it to be the most important unsolved problem in ...
, an important unsolved problem in mathematics
Places
*
RH postcode area, in the UK
* , an official name of Croatia in Croatian
*
Other uses
*
Rh (digraph)
This is a list of digraphs used in various Latin alphabets. Capitalisation involves only the first letter (''ch'' becomes ''Ch'') unless otherwise stated (''ij'' becomes ''IJ'').
Letters with diacritics are arranged in alphabetic order accordin ...
*
The Right Honourable, an honorific preceding a name in the UK
*
Radical honesty, the practice of always being completely honest and refraining from telling even white lies
See also
*
Royal Hospital (disambiguation) Several hospitals and former hospitals are known formally or informally as Royal Hospital or simply The Royal, indicating some form of royal patronage, such as sponsorship, usage, or creation by royal charter.
Australia
Melbourne
* Royal Child ...
{{disambiguation, geo