If an employer provides for the following particulars in a written agreement with the labor union that is organized by a majority of the workers at that workplace, if there is one, or with a person representing a majority of the workers at that workplace, if there is no such union, and the employer assigns a worker to the work stated in item (i), that worker is deemed to have worked the hours stated in item (ii), pursuant to the provisions of Order of the Ministry of Health, Labour and Welfare:
work which it is decided a worker will be assigned to, that is prescribed by Order of the Ministry of Health, Labour and Welfare as work that it is difficult for the employer to give concrete directions for, regarding things such as decisions about how the work is to be carried out and the allocation of time to that work, since, the way in which it is carried out needs to be left largely to the discretion of the worker who is engaged in that work owing to the nature of the work (referred to "covered work" below in this Article);
the hours that will be calculated as the working hours of a worker engaged in covered work;
that the employer will not give concrete directions to a worker engaged in covered work regarding things such as decisions on how the covered work is carried out, and the time allocation to that covered work;
that, pursuant to the provisions of the agreement, the employer will take measures to ensure the workers' health and welfare that are in line with the working hours of workers engaged in covered work;
that, pursuant to the provisions of that agreement, the employer will take measures to process complaints from workers engaged in covered work;
beyond what is provided for in the preceding items, particulars prescribed by Order of the Ministry of Health, Labour and Welfare.
前各号に掲げるもののほか、厚生労働省令で定める事項
The provisions of paragraph (3) of the preceding Article apply mutatis mutandis to the agreement referred to in the preceding paragraph.
略称規定第三十八条の三第一項第一号・この条の中だけ
…当該業務の遂行の手段及び時間配分の決定等に関し使用者が具体的な指示をすることが困難なものとして厚生労働省令で定める業務のうち、労働者に就かせることとする業務（以下この条において「対象業務」という。）
わかりやすく言うと
仕事の進め方を大きく労働者の裁量に任せる必要があり、使用者が手段や時間配分を具体的に指示しにくい業務として厚生労働省令で定めるもののうち、労使の書面による協定で労働者に就かせることにした業務のことです。