31.1.2019 EN Official Journal of the European Union L 30/51 ANNEX IX AUTHORISATION FORM FOR THE SUPPLY OF TECHNICAL ASSISTANCE REFERRED TO IN ARTICLE 21(1) Technical specification: The following form shall measure 210 × 297 mm with a maximum tolerance of 5 mm less and 8 mm more. The boxes are based on a unit of measurement of one tenth of an inch horizontally and one sixth of an inch vertically. The subdivisions are based on a unit of measurement of one tenth of an inch horizontally.