The Lower Sorbian vocabulary is relatively well described. Although so far there is no systematic comprehensive study of loanwords in Lower Sorbian, there exist some dictionaries, the Sorbian Language Atlas and quite a lot of detailed research literature. In most cases the loanword status of a given word is determined on the basis of these sources.
0 (No evidence for borrowing)
Words that are shown to be inherited from Proto-Slavonic or from an older historical stage of Sorbian without having been borrowed into it.
1 (Very little evidence for borrowing)
Mainly words of unclear etymology, but without further or only with meanwhile disproved indication that they are borrowed. In some other cases there is some indication that an indigenous word was replaced by a German loanword and later reborrowed from Upper Sorbian.
2 (Perhaps borrowed)
Mainly words of unclear etymology, but with some indication that they are borrowed. In some other cases it seems possible that an indigenous word was replaced by a German loanword and later reborrowed from Upper Sorbian, but it cannot be excluded that the original Lower Sorbian word had coexisted with the German loanword, although being less frequent than the loanword.
3 (Probably borrowed)
Mainly words generally considered to have been borrowed, but where there is still some doubt about it. One group of words within this category consists of items that are probably borrowed from Upper Sorbian but could also have been built on a Lower Sorbian basis under Upper Sorbian influence.
4 (Clearly borrowed)
Words generally considered to have been borrowed and where there is no doubt about it. Words not yet documented or not explicitly characterized as loans are assigned to category 4 if their status as a loanword was obvious (e.g. ocean < NHG Ozean ‘the ocean’).