For more information on frequently used technical terms, see also the XMM Glossary.
| Acronym | Explanation |
|---|---|
| ADU | Analogue to Digital Unit |
| ACIS | AXAF CCD Imaging Spectrograph |
| ADU | Analogue to Digital Unit |
| AHF | Attitude History File |
| AMA | Absolute Measurement Accuracy |
| AO | Announcement of Opportunity (AO-1) |
| AOCS | Attitude and Orbit Control and Measurement Subsystem |
| AMS | Archive Management Subsystem |
| AXAF | Advanced X-ray Astrophysics Facility |
| CAL | Calibration Access Layer |
| CCD | Charge Coupled Device |
| CCF | Current Calibration File |
| CTE | Charge Transfer Efficiency |
| CVZ | Continuous Viewing Zone |
| DEC | Declination,  (J2000) |
| DPU | Digital Processing Unit |
| EPIC | European Photon Imaging Camera |
| ERMS | EPIC Radiation Monitor Subsystem |
| ESTEC | European Space Research and Technology Centre |
| EW | Equivalent Width |
| FAQ | Frequently Asked Question |
| FITS | Flexible Image Transport System |
| FM | Flight Module |
| FOV | Field Of View |
| FWHM | Full Width at Half Maximum |
| GO | Guest Observer |
| GT(O) | Guaranteed Time (Observer) |
| GTI | Good Time Interval |
| GUI | Graphical User Interface |
| HEASARC | (NASA) High Energy Astrophysics Science Archive Research Center |
| HED | High Energy Detector (of the ERMS) |
| HEW | Half Energy Width |
| HER | RGS high event rate (selectable mode) |
| HETG | ( AXAF) High Energy Transmission Grating |
| HRC | ( AXAF) High Resolution Camera |
| HTR | High Time Resolution (mode of the RGS) |
| LED | Low Energy Detector (of the ERMS) |
| LETG | ( AXAF) Low Energy Transmission Grating |
| LSF | Line-spread Function |
| METG | ( AXAF) Medium Energy Transmission Grating |
| MOC | XMM Mission Operation Centre |
| MOS | Metal Oxide Semi-conductor |
| OBDH | Onboard Data Handler |
| OCB | On-Chip Binning |
| ODF | Observation Data File |
| ODS | Observation Data Subsystem |
| OGIP | (NASA's) Office of the Guest Investigator Program |
| OM | Optical Monitor |
| OTAC | Observatory Time Allocation Committee |
| PHA | Pulse Height Analyser |
| PHS | Proposal Handling Subsystem |
| PI | Principal Investigator |
| PPS | Pipeline Processing Subsystem |
| PSF | Point-Spread Function |
| PV | Performance Verification |
| QE | Quantum Efficiency |
| RA | Right Ascension,  (J2000) |
| RFC | RGS Focal Camera |
| RFS | Refreshed Frame Store mode of EPIC MOS |
| RGA | Reflection Grating Assembly (of the RGS) |
| RGS | Reflection Grating Spectrometer |
| RPE | Relative Pointing Error |
| XRPS | Remote Proposal Submission |
| SAS | Science Analysis Subsystem |
| SDF | Slew Data File |
| SER | RGS split event reconstruction (selectable mode) |
| SES | RGS single event selection (selectable mode) |
| SGS | Sequence Generator Subsystem |
| SMP | Science Management Plan |
| SOC | XMM Science Operations Centre |
| SSC | Survey Science Centre |
| SSD | Software Specification Document |
| TBC | To Be Confirmed |
| TBD | To Be Determined |
| TOC | Table of contents |
| ToO | Target of Opportunity |
| UHB | XMM Users' Handbook |
| URD | User Requirements Document |
| URL | Unique Resource Location |
| W90 | 90% energy width |
| WWW | World Wide Web |
| XDA | XMM Data Archive |
| XID | X-ray source identification (by the SSC) |
| XMM | X-ray Multi-Mirror Mission |