| Revision no. | Date | Author | Comments |
| 0.1 | 1997-10-10 | UL | draft |
| 1.0 | 1998-01-30 | UL | submitted for task approval |
| 1.1 | 1998-03-19 | UL | updated section on selection capabilities; brought in line with version 1.0 |
| of code; ; SSC/SOC comments incorporated | |||
| 1.2 | 1998-05-26 | UL | minor modifications |
| 1.3 | 1998-06-26 | UL | replaced section with selection capabilities by reference to selectlib documentation; minor other modifications |
| 1.4 | 1998-08-03 | UL | added TODO section to developers notes; updated parameter section to bring it in line with selectlib v3.6 |
| 1.5 | 1998-08-26 | DH | update parameter list and TODO section |
| 1.6 | 1999-01-19 | DH | update parameter list |
| 1.7 | 1999-05-12 | UL | very minor updates |
| 1.8 | 1999-05-28 | DH | update parameter list and other changes related to new parameter names |
| 1.9 | 1999-07-6 | DH | update parameter list |
| 1.10 | 1999-07-30 | DH | add zcolumn error parameter; remove all mention of second order products from the task description, as this functionality has been moved to the tabcalc task. |
| 1.11 | 1999-08-05 | DH | properly update documentation of use of the table parameter. |
| 1.12 | 1999-08-26 | DH | several minor fixes. |
| 1.13 | 1999-09-06 | UL | removed all vspaces / proper usage of warn macro |
| 1.14 | 1999-09-13 | DH | updates to macros and error/warning messages. |
| 3.7 | 1999-12-20 | DH | Change to version numbering scheme. Update documentation for new histogramming product and new image binning scheme. |
| 3.8 | 2000-01-26 | DH | Add documentation for data subspace support. |
| 3.14 | 2000-02-17 | DH | Add documentation for update of exposure information. |
| 3.15 | 2000-02-21 | UL | Brought description of flagbit/flagcolumn in line with changes in selectlib-4.28. |
| 3.20 | 2000-03-22 | DH | Minor update to documentation on exposure information. |
| 3.25.1 | 2000-06-01 | DH | Update default parameter values. Update error and warning messages. |
| 3.25.3 | 2000-06-09 | DH | Major upgrade to ``Extraction Stage'' section. Reorganization of ``Parameter'' section. Several other minor updates. |
| 3.25.4 | 2000-06-15 | DH | Try and fix subsections in Parameter section. Update exposure error/warning messages. Fix misuse of task macro . |
| 3.25.5 | 2000-06-21 | DH | Add documentation for new attributestocopy parameter. |
| 3.25.6 | 2000-06-22 | DH | Add documentation for the light curve keywords E_MIN, E_MAX and E_UNITS. |
| 3.26 | 2000-07-18 | DH | Add documentation for BACKSCAL keyword calculation. Update error/warning message. Fix SSC SPRs 1895 and 1896. Add documentation for the squarepixels parameter. Update external packages macros. |
| 3.27 | 2000-07-20 | DH | Update warning messages. |
| 3.30 | 2000-09-22 | DH | Add documentation for the ignorelegallimits parameter. Remove MaxDataRange and MinDataRange warnings. |
| 3.31 | 2000-10-03 | DH | Add documentation of the calculatebackscale parameter. Warn users about limitations of the BACKSCAL keyword calculation. |
| 3.32 | 2000-10-09 | DH | Add documentation for the filterexposure parameter. Update documentation for writing of exposure information to products. |
| 3.32.1 | 2000-10-12 | DH | Add description for the dssclean parameter. |
| 3.32.4 | 2000-10-27 | DH | Update warning messages for empty tables. |
| 3.36 | 2001-07-20 | DH | Remove documentation concerning evselect calculating the BACKSCAL keyword. Update some error and warning messages. |
| 3.37 | 2001-08-13 | DH | Add documentation for the ExpBadDss warning message. |
| 3.38 | 2001-09-17 | DH | Update warning and error messages for the exposure correction part of the code. |
| 3.40 | 2001-10-11 | DH | Add documentation for new weighted column features, including the production of rate spectra for Xmm data sets. |
| 3.42 | 2001-10-11 | DH | Mention task imagechain as an example of using evselect in a script. |
| 3.43 | 2001-10-29 | DH | Add documentation for shifting an image to be centered on a given ra and dec. Remove documentation for the makesparserates parameter, and add documentation for the makeratecolumn parameter. Add description of binning scheme for integer-valued columns. |
| 3.45 | 2001-11-11 | DH | Change formatting of parameter section subsections. |
| 3.47 | 2001-11-11 | DH | Add HistoColumnName warning to the documentation of warning messages. |
| 3.47.1 | 2002-01-25 | DH | Correct formatting of subsections in the task parameter list. Add warning about light curve exposure correction (or lack thereof). |
| 3.47.1 | 2002-02-28 | DH | Add documentation for new warning message, NoExpEmpty. |
| 3.47.3 | 2002-05-16 | DH | Update documentation with respect to use of zcolumn and associated parameters. |
| 3.54 | 2002-10-15 | DH | Add description of keywords written to images specifying the physical coordinate system. Add sentences about propagation of extensions to output event lists. |
| 3.55 | 2002-10-23 | DH | Update documentation to reflect new parameter system and the automatic setting of controlling parameters. |
| 3.56 | 2003-01-27 | DH | Remove mention of imagechain task, as it is not part of the public distribution. |