diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs
index 6e03911f7d..f52d12368e 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Search/ISearchStrategy.cs
@@ -17,13 +17,17 @@ namespace ICSharpCode.AvalonEdit.Search
///
/// Finds all matches in the given ITextSource and the given range.
///
- /// This method is thread-safe. Implementers must guarantee this!
+ ///
+ /// This method must be implemented thread-safe.
+ /// All segments in the result must be within the given range, and they must be returned in order
+ /// (e.g. if two results are returned, EndOffset of first result must be less than or equal StartOffset of second result).
+ ///
IEnumerable FindAll(ITextSource document, int offset, int length);
///
/// Finds the next match in the given ITextSource and the given range.
///
- /// This method is thread-safe. Implementers must guarantee this!
+ /// This method must be implemented thread-safe.
ISearchResult FindNext(ITextSource document, int offset, int length);
}