A German-Latvian dictionary Liber memorialis Letticus (1748) compiled by Caspar Elvers (1680–1750), the pastor of the Latvian parish at St John’s church in Riga, is the second printed bilingual dictionary with Latvian as the target language in Livonian-Couronian tradition after the pioneering work Lettus (1638) compiled by Georg Mancelius.

The little interest in this source could be the reason why researchers had not discovered that one of the seven copies of the dictionary at the Academic Library of the University of Latvia in Riga partly differs from others. This copy does not have a printed title page and the first nine sheets (A–J, pp 1—144) are not identical with these sheets in the other copies. Differences between the versions are seen in all the levels of the Latvian part of the text.

The comparison of two versions of the first nine sheets of Elvers’s Liber memorialis Letticus enables to assume that the newly found version is probably an earlier copy than the regular one. It may represent the initial shape of the dictionary, which might have already been printed in 1734. Several questions still remain – is the author of both versions the same person; who could be the possible assistant of Caspar Elvers in preparing the final version of the dictionary. The answers to these questions could help to clarify the history of the Latvian lexicography in the middle of the 18th century.