The tables relate to England's maintained and independent secondary schools and colleges, excluding special schools.
They are listed in various ways within each local education authority: alphabetically, and ranked on key indicators from their GCSE and equivalent results, A/AS-level results and value added measures for 2004.
These statistics were first published by the Department for Education and Skills in January 2005 (the tables based on the 2005 exam results are due to appear in January 2006).
We republished our tables in October 2005 to include the new GCSE-level benchmark the government is going to introduce: the proportion of students in each school getting the equivalent of at least five grades A* to C including English and maths GCSEs.
The results for each school are collected by the department but have not been made public until now. They were obtained by the BBC under the Freedom of Information Act.
Some independent schools apparently do badly on the new measure because students take International GCSEs, which are not recognised in government achievement data.
Smaller schools with fewer than 30 candidates are not ranked, although for completeness they are included in the alphabetical lists.
Independent schools have (IND) after their name, academically selective schools have (SEL).
Clicking on any establishment's name in the lists takes you to a page showing its results and other information.
After the school's name and address comes information about its TYPE, admissions policy and any specialism. See the end of this article for more detail on this.
The ABSENCE figures are the percentage of half day sessions missed by pupils, with and without the school's authorisation: "negligible" means less than 0.05%.There is a link to the alphabetical list of all schools in the same local education authority.
And there is a link to the page on the Ofsted website where the institution's most recent inspection report can be found.
The school's results are then presented as graphs as well as in figures. The graph bars allow a quick comparison between the school's results and the highest ranking school in that category, as well as showing local and national averages where applicable.
The GCSE-LEVEL figure is the percentage of pupils who achieved five or more GCSEs at grades A* to C or their equivalents.
The tables we republished in October 2005 include a NEW measure: that the "five or more good GCSEs" include English and maths GCSEs.
The government is introducing this benchmark in response to concern that youngsters lack basic literacy and numeracy, even though they have apparently good exam results.
The OLD measure allows for a range of vocational "equivalents", vastly expanded by the Department for Education and Skills in 2004 to include a host of vocational qualifications approved by the Qualifications and Curriculum Authority (QCA) and too numerous to list.
As a tie-break, schools achieving the same rank are further ranked on the average point score achieved by students.
The number "eligible" to take the exams is followed by the percentage of them with special educational needs, with or without statements.
The results for the previous three years, on the old measure, are also listed. But care is needed in looking at the trend because of the inclusion of a wider range of qualifications this year.
Independent schools choose whether or not to be included in the performance tables. They do not have a local education authority (LEA) but are grouped with other schools in their geographical area.
The averages for an area are for the state schools in the relevant LEA, though the national averages do include independent schools.
The DfES defines the year group as being those who were 15 at the start of the academic year, but counts their results from whenever they were taken even if they have since moved to a different school.
NA in the tables indicates that there is no data or that the category is not applicable. Reasons vary: for example it might not have had any relevant exam entries in a particular year.
VALUE ADDED: PUPILS' IMPROVEMENT
The results incorporate a complex Key Stage 2 to GCSE value added score designed to show the progress children have made.
This is done by comparing their achievements with those of other pupils nationally who had the same or similar prior attainment in their test results at age 10 or 11 in 1999.
The pupils' individual scores are averaged to give a score for the school as a whole, represented as a number based around 1000.
The "bottom" to "top" range is 882 to 1099.8. Those on scores of 1056.6 and above are in the top 5% of schools nationally, those on 937.1 and below are in the bottom 5%.
The Department for Education says that if every pupil in a school achieved the median (middle) outcome for pupils with their level of prior attainment, the school would score 1000.
Differences of up to 29.1 should not be regarded as significant in the case of comparisons between schools with about 50 pupils. For about 100 pupils, differences of up to 20.6 should not be seen as significant.
If less than half a school's 15-year-olds were included in the calculation, the result is not published.
The value added data are those originally published in January 2005 and are not affected by the new GCSE benchmark.
The A/AS-LEVEL shows the average point score per student at the end of two years' study. On the bar, "top" is 512.6 points.
Most people study for AS-levels in their first year then A-levels in the second. The results for the two most recent years are given - though where someone did an AS and an A-level in the same subject, only the A-level is counted.
The points are those used by the Universities and Colleges Admissions Service (Ucas). As an example, an A-level grade A scores 120 points, an AS-level grade A is 60 points.
In the rankings, any ties are broken on the number of entrants - more first - then alphabetically.
Links at the foot of each school page are provided to compare its performance with that of other schools.
Academy (City Academy) - independent state schools where sponsors invest in the building or modernisation of the premises and the state meets running costs.
Community school (formerly county school) - maintained by the local education authority (LEA), which is responsible for the school's admissions policy.
Voluntary aided - maintained by the LEA, with a foundation (generally religious) which appoints most of the governing body, which is usually responsible for the school's admissions policy.
Voluntary controlled - maintained by the LEA, with a foundation (generally religious) which appoints some governors.
Foundation school (usually formerly grant-maintained) - may have a foundation (generally religious) which appoints some of the governors. Maintained by the education authority but decides its own admissions policy.
City Technology College or City College for the Technology of the Arts - an earlier form of Academy.
IND - Independent school - mostly fee-paying.
Comprehensive - takes all pupils, usually regardless of their ability, aptitude, or whether they have been selected for a place at a selective school.
Secondary modern - takes pupils regardless of their ability or aptitude and who have not been selected for a place at a selective school.
SEL - selective - takes pupils depending on their ability or aptitude.
Non-selective - independent school which takes pupils usually regardless of their ability or aptitude.
Boys, Girls ... - shows whether or not the school's intake is single sex.
The age range is self-explanatory - though a school might have a sixth form which is not officially part of the school roll.
In addition, many schools have a "specialist" status:
Business and enterprise
Maths and computing