School admissions has become one of the most contentious topics for parents seeking places for their children in the best available schools.

League tables and inspection reports have highlighted the most and least successful schools, creating a high demand for places in the "best" - and a corresponding reluctance to send children to local schools at the bottom of the league tables.

Admissions factors

Brother or sister at the school Distance from the school Ease of access by public transport Medical or social grounds Parental preference Attending a 'feeder' primary school Maximum infant class sizes

How parents get their children into their first choice school has become the subject of much effort, expense and dispute - with appeals against admissions decisions rising sharply in recent years.

Parents are asked to say where they would most like their children to attend, and in England about 85% get what they want - but many are allocated places somewhere other than their first selection.

Disappointments - and the number of appeals - are much higher in London.

So what are the rules by which schools admit pupils where there are more applications than places?

In fact there are no standardised rules for school admissions, but there are guidelines - described by the Department for Education as "commonly used and acceptable criteria".

And a code of practice requires schools and local authorities to ensure that guidelines for admissions are available to parents.

Hardships

The factors for allocating places will vary from school to school and have different priorities, but they are likely to give preference to pupils with a brother or sister at the school and those who are nearest to the school.

In some areas, parents can be left having to get their children of different ages to two or more different schools each morning, because no priority is given to siblings of pupils already at a school.

In other cases, siblings are the top priority - so someone living next door to a school loses a place to someone living miles away who happens to have a brother or sister there already.

For non-selective primary and secondary schools, there are no fixed catchment areas which automatically qualify pupils for places in schools, but proximity is usually a major factor in determining admissions.

Guidelines usually set out in painstaking detail just how this is to be measured. For example:

The distance between the family's normal home address and the school's nearest entrance gate: closest first. The shortest designated route is a public route with a proper made up surface, such as tarmac or concrete. If it is a road, it does not have to have a separate pavement.

This importance of proximity stretches across local authority boundaries, so that children near to the boundaries of a local education authority can apply for places in their own or a neighbouring authority.

Other factors

The pursuit of places has pushed up house prices around popular schools, as parents seek to buy into these areas.

There have also been cases where parents have falsified addresses or used relatives' addresses to increase their children's chances of admission - or bought a flat near a school to acquire a local address, then rented it out.

Schools have become wise to this and are now much more careful about checking where the family home is.

Whether a child has attended a "feeder" primary will be a factor for secondary schools, but for entrance to primary schools, attending an attached nursery school is not allowed to influence the allocation of places - whatever people think.

In religious schools, an adherence to that religion can be a determinant in allocating places - including requirements such as attendance at services or a letter from a minister of religion.

In primary schools, classes for five, six and seven year olds have a maximum upper size limit of 30, which can place an absolute limit on applications - overruling factors such as proximity or parental preference.

Anger

The failure to find places in schools sought by parents has prompted some protracted disputes.

In the school year 1999-2000 there were parental boycotts of schools allocated by the council and the setting up of alternative temporary classrooms in places including Leicester and Kingston-upon-Hull.

If parents feel that their applications have been unfairly considered there is an independent appeals procedure in which local tribunals can review schools' admissions decisions.

Where there is selection or partial selection, places can be given according to ability, which can be determined by tests or interviews.