The government has published new school league tables data showing the role of vocational courses in GCSE scores - which schools rely on them most (see table below)?
Education Secretary Michael Gove has said he is worried that the existing system creates incentives for schools to encourage students to take "low quality" vocational courses, to boost their places in the league tables.
Government officials describe it as "gaming" the system.
Vocational courses - in subjects like catering, travel and tourism, life skills and IT - can count for up to four GCSEs.
Some were heavily criticised as being of little value in a recent government review - though many others were considered to be higher quality.
Schools have long been rated on the "benchmark measure" of the percentage of pupils getting five A*-C grade GCSEs, or equivalents - although English and maths GCSE were added to the measure in 2007, because of fears that schools were relying too much on vocational equivalents.
The data published on Thursday shows the proportion of children getting five A-C passes, including maths and English, but it gives two columns - one including, and one excluding, non GCSE equivalents.
The gap between the two figures shows the extent to which the school is dependent on vocational equivalents for its GCSE figures.
Nationally, in all state schools, the proportion of students gaining the GCSE benchmark drops from 55.2% to 50.5% when vocational equivalents are excluded.
For academies - many of which were set up in a drive to turn around failing schools - the gap yawns much wider, with 44% dropping to 33% when non-GCSE courses are removed.
The table below is a list of the 200 schools in England with the highest dependence on vocational equivalent courses - those most likely to be accused of "hiding" behind vocational courses.
Top of the list is the Steiner Academy in Hereford, which offers an alternative curriculum based on the principles of Rudolf Steiner - merging the practical, artistic and intellectual and allowing students to learn in individual ways.
The school offers only four accredited qualifications - but say students go on to A-level and university study successfully, with very positive feedback from sixth-form colleges.
"It goes to show a programme doesn't have to lead to a GCSE to be high quality, broad, substantial and balanced," says headmaster Trevor Mepham.
Second was Heath Park Business and Enterprise College in Wolverhampton, a school classed as "outstanding" by Ofsted, which has seen the proportion of pupils gaining the GCSE benchmark rise from 42% to 74% over the past four years.
No-one at the school could be reached for comment, but on its website, it says its priorities are that children "be happy", "have a wide range of learning opportunities in and out of the classroom", and "are encouraged to achieve their full potential whatever their abilities".
Third on the list was Fyndoune Community College in Durham.
It too has seen a rapid rise in pupils attaining the GCSE benchmark, from 26% in 2008 to 64% in 2010.
Principal Trevor Dunn points out that this includes English and maths "'proper' GCSEs" in which students did "incredibly well... far, far better than could have been predicted".
"In our view, maths and English tells the story - you can't fudge maths and English," he says.
The school's intake comes from a "relatively socially deprived community", he says, and students are offered a mixture of academic and vocational qualifications - as well as the opportunity to study on an on-site farm.
"We believe we're not just preparing students for government measures, we're preparing students for life," he says.
Even so, Mr Dunn welcomes the introduction of the English Baccalaureate.
Even though languages have not been a priority for the school in the past, he wants to invest in "state of the art" language facilities.
"We live in an ever smaller global community and we probably are at a point where we believe having some language skills is a useful thing - it's what I would call a vocational skill really," he says.
Education Secretary Michael Gove says he aims eventually to rework the equivalent scores given to vocational courses, with some still be considered to be worth at least one GCSE.
He admits that as academies and other schools are turned round, and surge up the league tables, vocational equivalents often play a major role.
"If we look at schools that have been underperforming - as they go on a journey to improvement, they tend to use equivalents - but as they become stronger, their reliance on equivalents diminishes."
But with the government's emphasis on traditional subjects, particularly through the English Baccalaureate, the National Union of Teachers is concerned that schools are no longer clear where the goal posts lie:
"As the Government goes down the route of championing vocational education they need to make their mind up as to whether all qualifications are of value, or if it is simply particular academic subjects which carry weight when judging a school," said general secretary Christine Blower.
The table shows the roughly 200 schools in England whose GCSE benchmark scores drop most when equivalents are removed. AC denotes academies.