The online help says :
By default, CintaNotes searches only from the word boundaries. This means that e.g. when you search for "nation", notes containing the word “international” won’t be found. If you want to search also inside of words, you need to activate the Search Inside Words option.
However, leaving Search Inside Words unchecked, and searching for "interna" anywhere brings many instances of "international", as well as "internal". Checking Search Inside Words in that case does increase the count of notes found (but there are two many for me to understand the difference).
It seems Search Inside Words makes (uncorrectly) an exception for strings at the beginning of a word.
This is verified by searching for "gero" with Search Inside Words unchecked, which brings only a few notes including words beginning with "gero" (obviously no such complete word) ; whereas checking Search Inside Words brings up a whole lot more, containing "dangerous" and "dangerously".
Similarly, searching for "dential" with Search Inside Words unchecked brings up almost nothing, however checking Search Inside Words brings up a great number of notes containing "confidential", "presidential" and such.
Another, associated bug is that sometimes, searching will bring up notes with no characters highlighted, so you won't know why they have been found (or whether they should have been).
In the above example, searching for "dential" with Search Inside Words unchecked brings up only 4 notes among 2 000, none of them having anything highlighted at all.
Opening them one by one and using the Search function within the editor shows they should not have been found : none of them include a "dential" word, however all of them include words such as "presidential" or "credentials".
In that example, the search function within a note works correctly, finding nothing when Search Inside Words is unchecked, and finding "presidential" and such when it is.
Reflecting the global search function behaviour, searching "interna" with the search function within a note will find "international", whether Search Inside Words is checked or not, which is incorrect.
CN v.3.8 portable
Windows 7 64-bit