Maintenance experience should be written up in a manner that the reader has a reasonable understanding of where, when and what maintenance constitutes the experience. A task-by-task account is not necessary, but at the same time a bland statement such as “X years maintenance experience completed” would not be acceptable. A maintenance log book detailing the experience is desirable and some competent authorities may require such a log book (see AMC 66.A.10).
Consequently, the format used to evidence the maintenance experience is not strictly defined in the rules and is left at the discretion of the competent authority issuing the licence. Hence, EASA advises you follow the instructions of the competent authority where you intend to apply for.