The Monday morning ritual was as much a part of my schooldays as the register, algebra and detention. If the form teacher called out your name, you would come up to the front and hand over your dinner money for the week in an envelope.
Those who weren't summoned up were on free school meals. And just in case the distinction was lost on the rest of us, they were given different-coloured lunch tickets to use in the canteen.
Mercifully, we now live in more enlightened times than the stigmatising world of a provincial grammar school in the early 1970s. Today, only the head and the bursar will know which pupils pay for their lunches and which don't. There's no roll-call, no colour-coding and no separate queues, another feature of some of my contemporaries' schooldays.
But far from fading from any sort of public scrutiny, free school meals entitlement – FSM, in education jargon – is all of a sudden being talked up and aggressively marketed. Heads send out desperate flyers to parents urging anyone who might – just might – qualify to sign up. One big comprehensive in our area even demands a doctor's note if you want to bring packed lunches. The stated reason is health concerns – too much chocolate and crisps in the sandwich boxes – but as a consequence, intended or not, parents report that FSM figures are climbing.
And boosting your FSM numbers is currently the name of the game as far as the Department for Education is concerned. The national average is somewhere between 13 and 15 per cent of pupils. If your school is languishing in single digits (a 2005 report by the Sutton Trust showed that at the 200 highest-achieving state schools it was just 3 per cent), it will immediately come under suspicion of "cheating" on its admissions to favour middle-class homes. High levels of social deprivation in pupils' backgrounds are linked by study after study with academic underachievement. Another recent report shows that 66 per cent of those in the bottom fifth of GCSE results nationally live in the poorest fifth of households.
Being accused of cheating, though, is not the only consequence for schools with low FSM figures. They will also miss out on various pots of additional money earmarked by local education authorities for those primaries and secondaries coping with the greatest social needs. So Westminster City Council, for instance, is currently restructuring provision of nursery places in its primary schools according to numbers on FSMs. Above average figures indicate deprivation and so that school gets more full-time nursery places. Below average ones suggest a more affluent catchment area and so a cut in funding for three to four-year-olds.
And the FSM figures are set to become even more crucial under the Coalition Government's flagship education plans. The "pupil premium", a key plank of both Liberal Democrat and Conservative strategy, will provide schools with an extra £430 a year per pupil eligible for FSMs. Hang on to that word "eligible", class. I will come back to it in a moment.
Applicants who qualify for FSMs are also to be given priority in admissions to new academies. And under plans to tackle low numbers of youngsters from poorer homes going to university – official figures given by the Universities minister, David Willetts, in 2010 show that 15 per cent of those on FSMs go on to take a degree, compared with 33 per cent of the rest – Nick Clegg intends to offer disadvantaged teenagers two years' free university tuition. The qualifying criterion? You've guessed it: FSMs.
Which would make good sense if FSM statistics were a reliable indicator of real need. But many educational experts and anti-poverty campaigners have their doubts. "They can be a very crude measurement around university access," concedes Dr Lee Elliot Major, research director of the Sutton Trust, which works to improve educational opportunities for youngsters from non-privileged backgrounds. "We have found the figures to contain all sorts of discrepancies," says John Dickie, head of the Child Poverty Action Group (CPAG) in Scotland.
One of the major flaws of the current FSM arrangements was highlighted by author Susannah Hickling in this month's edition of Standpoint, the political and cultural magazine. "I'm a lone parent [of a seven-year-old son] and a freelance writer who regularly earns below the £16,000 annual threshold for free school dinners, but my son isn't entitled to eat lumpy mash for nothing because I receive Working Tax Credit."
Leaving aside her damning verdict on Jamie Oliver's crusade to banish lumpy mash (along with Turkey Twizzlers) from school canteens, Hickling's case highlights the failure of FSM provision to include many on low incomes. If you work more than 16 hours a week and top up meagre wages with Working Tax Credit, you are excluded.
Hickling, and others in the same boat, may well count under a range of other indicators of poverty. There is, for instance, the Government's favoured measure, which includes all those living in households where income is 60 per cent or less of the national average. That suggests that in England and Wales 23 per cent qualify as poor, way above the 13-15 per cent on FSMs.
This flaw was highlighted in a 2007 report by CPAG Scotland. It showed that less than half of children of school age in Scotland who were judged to be living in poverty by a range of other indicators qualified for FSMs. An estimated 150,000 were missing out.
"Are you sure that's right?" queries a Department for Education spokeswoman when I place the conundrum before her. "It doesn't sound right, does it?" She promises to get back to me when she has checked up with colleagues. "I know it is all very complicated," she says as she signs off.
The department's own website seems very clear on who does – and who doesn't – qualify. It is a yes if you are on Income Support, Income-Based Jobseeker's Allowance, Income-Related Employment and Support Allowance, or support under Part VI of the Immigration and Asylum Act of 1999 (but not, presumably, under parts I to V). Also included are those receiving Child Tax Credit, but not if they are also getting Working Tax Credit.
The secretary at my local primary school offers a simpler formula when I drop in to enquire about the system. "Basically, if you are on benefit, you qualify," she says through the sliding glass window next to the school's main entrance (some things never change), "but there is a difference between qualifying and receiving."
And that is another of the major drawbacks of the FSM figures. There is not one but two sets. Ministers tend to range freely between them to suit their particular purposes on that occasion. Sometimes they quote the figure for those actually receiving them. At others they reel off the numbers for those who are "known to be eligible". In Scotland, 13 per cent are in receipt of non-lumpy mash, and 19 per cent are "known to be eligible".
Six per cent may not sound like much, but it is a wide gap. If you calculate 6 per cent of the seven million children currently in English primaries and secondaries, that adds up to a disparity of 420,000. Add in 80,000 as a similar proportion of the school population in Wales, Scotland and Northern Ireland and you end up with a discrepancy of 500,000.
The source of the two streams of data is apparently straightforward – or so the Department for Education tells me when they come back to me 24 hours later. Once a school offers your child a place, you are sent a form to fill in which includes the offer of FSMs. Those who tick the box do not have to send in any supporting paperwork (unless they receive Child Tax Credit), but their names are then checked against a national database held by the Department for Work and Pensions. If the computer says yes, they are eligible. Hence the "known to be eligible" figures. But not everyone then goes on to take up the offer. Those who do make up the "recipient" numbers.
But is it really credible that 500,000 schoolchildren are declining the offer of Jamie's new, improved FSMs? That one manages to wrongfoot even my friendly school secretary. "You've got me there," she replies. "We've only had one parent who applied, got the green light and then refused."
There are various potential explanations. Another of the curiosities of FSMs is that further education colleges do not offer them. So if your 16- to 18-year-old is going to one to do his or her A-levels, rather than a school sixth form, they will go down as eligible but not in receipt. This creates particular problems with the university admission figures.
And it may be that parents apply without thinking it through, and only reach a final decision – for example, if their children are fussy eaters and need packed lunches – only when they are told they are eligible. It sounds an odd way of approaching things, but that, I suppose, is the logic of the figures.
How, then, in all this muddle, might the FSM figures be consolidated into a single set of statistics robust enough to take the weight that they must now carry in dictating policy on reducing the lifelong consequences of poverty? Dr Lee Elliot Major at the Sutton Trust has a simple request of the Government. "We have been advocating for a while that a measure called 'Ever FSM' be used. Our research shows that 22 per cent of pupils are on FSMs at some stage in their school career. They may go on and off FSMs because, for instance, of fluctuations in their parents' employment. We would argue that once an entitlement is established, it should continue as long as you are at school [ie, do away with the current practice of an annual review]. If FSM is to be the measure, we should do everything to make sure it includes as many people as possible."
What of the various alternatives to FSMs as the gateway to additional educational support that have been trailed over the years? One measure that has been tested is "postcode analysis" – making an assumption about a pupil's home economic circumstances on the basis of the address they give on their application form. The drawbacks, though, are immediately apparent. In my London street, the row of terraced houses that all have the same postcode contain variously nine bedsitting rooms, a hostel for recovering alcoholics, the large, extended family of a factory worker, and the various comfortably-off domestic units of a television scriptwriter, an award-winning artist, and an accountant. Same postcode, radically different economic circumstances.
"The big advantage of FSM is that it is an individual measurement," Dr Elliot Major says. "So another approach might be for schools to compile a profile of each pupil's background when they join." But that would involve interviewing parents, and asking them about their professions and their income. Even if they agreed to divulge such details in our privacy-obsessed age, questioning along these lines would start alarm bells ringing once more about "backdoor selection".
When the 1944 Education Act established state-funded school places for all five- to 15-year-olds in Britain, school meals were included in the package as free for everyone. It was only in 1949, when the catering bill was getting too big, that means-tested charges were introduced – a flat rate of sixpence a week for those who could afford it. And that broadly remained the system until, last year, the Scottish Parliament was persuaded by a campaign spearheaded by CPAG to agree a non-binding commitment that school lunches would once again be free in Scotland for all children aged five to eight.
The actual funding of such a measure, though, was left up to local authorities, and only West Dunbartonshire, reports John Dickie of CPAG, has honoured that commitment, though others have done so partially. "It was a measure the SNP minority government supported, so we hope that now it has a majority, it will provide the resources needed to make it happen."
If the example of Westminster is anything to go on, Dickie may be waiting in vain. In June 2010, the Coalition Government scrapped a scheme agreed by its New Labour predecessor for a modest extension of FSM eligibility on the grounds of cost.
Part of the thinking behind such schemes is health-related – to improve the diet of young children – but the goal of eliminating any distinction in school between children of better-off families and those from low-income homes is also important. Such a universal benefit as FSMs-for-all would indeed catch everyone who needs them, but would also feed those who, in purely economic terms, do not. With the Coalition Government in London cutting back on child benefit, once available to all, the Scottish experiment is swimming against the national tide (though not the European one, with 90 per cent of schoolchildren in Finland getting FSMs and 85 per cent in Sweden).
And so, it seems, we are stuck with flawed FSM figures as the least bad alternative. No one appears enthusiastic about them, or to judge them as gospel. But no one has a ready alternative. In the Government's rush to tackle intractable issues of educational underachievement and lack of social mobility, the boring, detailed task of addressing the shortcomings of FSM figures is clearly regarded as too unimportant to delay the grand project. Even if it means their much-trumpeted reforms may be built on sand.