The lemmas used in the DÉCT are those of the Tobler-Lommatzsch electronic version, from which were also taken the digital indices of disambiguation (tor1, tor2, tor5, for ex.).

There are rare exceptions : like the Dictionnaire du Moyen Français, our dictionary makes, for ex., the distinction between afoler¹ (etymon : FULLARE) and afoler² (etymon : FOLLIS) or between assomer¹ (etymon : SOMNUS) and assomer² (etymon : SUMMA), while Tobler-Lommatzsch joins them.

For practical reasons, adverbs of manner ending with the suffix -ment do not appear in the DÉCT as in Tobler-Lommatzsch under the entry of the word they are derived from, but are extracted and given full lemma status.

However, it is mainly in the area of grammatical lemmas that this dictionary departs somewhat from the Tobler-Lommatzsch. It is a tricky field: lemma choices are sometimes questionable, grammatical analysis is often doubtful. This particularly applies to some of the noun determiners, which needed to be corrected (see, for example, the question of possessives and the creation of the lemma son4). The discarded lemmas can, in any case, be found at the T-L tag, in the list of dictionaries located under the entry.

In the case of proper nouns, when the forms did not appear in Tobler-Lommatzsch, we adopted the entries of Foerster-Breuer.