- When mentioning the full name of an artist (if known) their birth and death, these are considered an authentic work by this artist.

- Attribution: when we are in doubt about the authenticity of the work we use the terminology 'Attributed to ...'. This statement followed by the name of the artist indicates that the work was actually produced during the life of the artist and that there are serious indications that it is indeed the work of this artist fully or partially. The authenticity of the work is not completely secure and can be confirmed or rejected later by new elements or by thorough investigation.

- Workshop: the words 'studio ...' indicates that the work was produced in the studio of a famous master, under his supervision and possibly with his cooperation. The logical consequence is to date the work during the life of the aforementioned artist. If the workshop was active across generations, a clear timing must be given.

- With reference to the "school of ... 'the timing is less strict: it is a student of a certain master, but the term continues until 50 years after the death of the master. The words "school of ... ' ensures that the work was made during the existence of an artistic tendency whose exact date should be specified and whose author must have been in this group (eg. The school of Antwerp).

- Expressions such as' in the style of ... ',' along the lines of ... ',' genre ',' to ... "give no guarantee about the authenticity, the time, the school or the identity of the artist.

- 'Signed' followed by the name of an artist without birth and death gives no guarantee that the work was painted by the artist mentioned.

- The entry '(period) Louis XV / XVI' ... 'applies to a piece of furniture that actually dates from that period. The same applies to the naming of a well, followed by a reference to a certain period of time, for example. "Empire an armchair '. The addition "style" to a period of time such as' Louis XV-style "refers to an art object which was created at a later time.