Organisers of study holidays, or summer schools, lecture tours and similar programmes arranged on a commercial basis between educational organisations, universities and holiday organisations
Trefnwyr gwyliau astudio, ysgolion haf, teithiau darlithiau, a rhaglenni tebyg a gaiff eu trefnu’n fasnachol rhwng sefydliadau addysgol, prifysgolion a sefydliadau gwyliau