A GRAMMAR school was denied a top 10 place in annual league tables - because no one validated its A-level results.
Using newly-published statistics for the 2015/16 academic year, The Irish News this week listed the 30 schools with the best A-levels.
Securing three or more A-levels at grades A* to C is considered a reasonable expectation of grammar pupils, especially as most are geared towards taking these exams.
No results were made available by the Department of Education for Portora Royal and Collegiate Grammar in Co Fermanagh, which were merged to form the new Enniskillen Royal Grammar School.
Dr Neill Morton, the former head teacher of Portora, said he was disappointed by his school's exclusion.
With 87.7 per cent of pupils achieving three or more good A-levels, the school would have placed sixth overall.
The department told the Irish News that it "did not receive fully validated data for either Portora or Collegiate schools".
Only fully validated data, a spokeswoman said, was included in the Summary of Annual Examination Results database.
The results of the two closed schools were sent to Enniskillen Royal in October last year for validation. Dr Morton said while he was disappointed, he accepted that this was not a decision by departmental officials.
"In 2016, 87.7 per cent of our students achieved three subjects in the range A*-C. These results ranked Portora Royal School sixth in NI, and the highest ranking non-denominational school," Dr Morton said.
"At GCSE, all of our students achieved at least seven full GCSE subjects and a short course in RE at grades A*-C. 87 per cent of all the grades achieved by all students were at A*-B. All but one of these students achieved English at C grade or above, proving again the effectiveness of our literacy and SEN programmes."
Dr Morton said his school's excellent results were achieved in a rural grammar for boys, which had a higher percentage of pupils on free meals and with special educational needs than most other non-denominational grammar schools. While an over-subscribed grammar school, its intake at 11 has traditionally had a wide academic profile.
"The fact that these results were not accorded a place in the performance tables is a disservice to the teachers who cajoled, supported, challenged, and guided the students to achieve the high expectations we held of them," he added.
St Dominic's Grammar School for girls topped the annual list for the fourth year in a row.
