RF
Abbreviation with 7 meanings
| Stands for | Rheumatoid factor |
|---|---|
| Meanings | 7 |
| Categories | Medical, Science & Engineering, Sports, Technology & Computing |
| Also written | Rf |
RF has seven meanings. The most common are Rheumatoid factor (laboratory test) and Radio frequency (physics); it can also stand for Right fielder, Refills, Retention factor, Random forest and Rutherfordium.
Meanings of RF at a glance
| # | RF stands for | Context |
|---|---|---|
| 1 | Rheumatoid factor | Medical › Laboratory Test |
| 2 | Radio frequency | Science & Engineering › Physics |
| 3 | Right fielder | Sports › Baseball |
| 4 | Refills | Medical › Prescription |
| 5 | Retention factor | Science & Engineering › Chemistry |
| 6 | Random forest | Technology & Computing › Artificial Intelligence |
| 7 | Rutherfordium | Science & Engineering › Chemical Element |
1. Rheumatoid factor
Medical · Laboratory Test Abbreviations
Autoantibody, usually IgM, directed against the Fc portion of IgG and found in about 70 to 80 percent of people with rheumatoid arthritis. High titers are associated with more erosive joint disease and extra-articular features such as nodules.
Example: RF 112 and anti-CCP strongly positive with symmetric hand synovitis: seropositive RA.
RF is not specific: it also appears in Sjogren syndrome, hepatitis C, cryoglobulinemia, chronic infections and many healthy older adults. Both RF and anti-CCP count toward the 2010 ACR/EULAR classification criteria for rheumatoid arthritis. In cardiology and pediatric notes, RF can instead mean rheumatic fever.
2. Radio frequency
Science & Engineering · Physics Abbreviations · also used in technology
Electromagnetic frequencies used for radio communication, roughly 3 kilohertz to 300 gigahertz. RF signals carry broadcasting, mobile phones, Wi-Fi, Bluetooth, radar and satellite links, and RF energy also heats food in microwave ovens and tissue in medical ablation.
Example: The device passed RF exposure testing, with a measured SAR of 1.1 W/kg.
RF radiation is non-ionizing: it can heat tissue but lacks the energy to break chemical bonds the way X-rays do. Mobile phones sold in the United States must keep the specific absorption rate (SAR) below 1.6 watts per kilogram. "RF engineering" covers the design of antennas, amplifiers and transmission lines.
3. Right fielder
Sports · Baseball Abbreviations
Outfielder who covers right field, position number 9, usually the player with the strongest arm because of the long throw to third base.
Example: Ichiro's throw from RF cut down the runner at third.
Roberto Clemente, Hank Aaron and Babe Ruth all played right field. A "rifle arm" is the classic right fielder trait. In radio technology RF means radio frequency.
4. Refills (Rf)
Medical · Prescription Abbreviations
Prescription field stating how many times a prescription may be refilled after the original fill. Most noncontrolled prescriptions remain refillable for up to one year from the date written, depending on state law.
Example: Lisinopril 10 mg tab, #30, Rf x 11, take one by mouth daily.
Also written RF, Ref or "refills". The total supply authorized equals the original quantity plus all refills. On prescriptions, "PRN refills" (unlimited for one year) is permitted in some states but discouraged because it removes a checkpoint for monitoring.
5. Retention factor (Rf)
Science & Engineering · Chemistry Abbreviations
In thin-layer and paper chromatography, the distance a compound travels divided by the distance the solvent front travels, a number between 0 and 1. Rf values help identify compounds and choose solvent systems; chemists often aim for an Rf around 0.2-0.4 before running a column.
Example: The product spot had an Rf of 0.35 in 1:3 ethyl acetate/hexane.
Rf depends on the plate, solvent, temperature and chamber saturation, so values are compared on the same plate rather than looked up in tables. Often printed with a subscript f. In HPLC and gas chromatography the related quantity is retention time. Do not confuse it with RF for radio frequency, or with Rf, the symbol for rutherfordium.
6. Random forest
Technology & Computing · Artificial Intelligence Abbreviations
An ensemble machine learning method that trains many decision trees on random samples of the data and features, then combines their votes or averages. It is accurate, resistant to overfitting and works well on tabular data with little tuning.
Example: The RF model ranked payment history as the most important feature for predicting default.
Developed by Leo Breiman in 2001, building on Tin Kam Ho's random decision forests of 1995. It provides built-in feature-importance scores and an out-of-bag error estimate. Gradient-boosted trees often edge it out in competitions. In telecom and electronics RF means radio frequency.
7. Rutherfordium (Rf)
Science & Engineering · Chemical Element Abbreviations
Rutherfordium (atomic number 104) is the first transactinide element, sitting below hafnium in group 4. It has been made only a few atoms at a time, and its isotopes are short-lived, but experiments have confirmed that it behaves chemically like a heavier hafnium.
Example: Gas-phase chemistry showed that Rf forms a volatile tetrachloride, much like hafnium.
Groups in Dubna (1964) and Berkeley (1969) both claimed element 104 during the Cold War disputes known as the Transfermium Wars. The Soviet team proposed kurchatovium (Ku), while the Americans proposed rutherfordium, after New Zealand-born physicist Ernest Rutherford. IUPAC adopted rutherfordium in 1997.
Related abbreviations
More laboratory test abbreviations
- RADT – Rapid antigen detection test
- RBC – Red blood cell count
- RDW – Red cell distribution width
- Retic – Reticulocyte count
- RFP – Renal function panel
- Rh – Rhesus (D antigen)
- RI – Reference interval
- RPR – Rapid plasma reagin
See all 135 laboratory test abbreviations →
More physics abbreviations
- QED – Quantum electrodynamics
- QFT – Quantum field theory
- QM – Quantum mechanics
- radar – Radio detection and ranging
- RHIC – Relativistic Heavy Ion Collider
- SEM – Scanning electron microscope
- SHM – Simple harmonic motion
- SLAC – SLAC National Accelerator Laboratory
See all 68 physics abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.