diff --git a/lib/zstd_static.h b/lib/zstd_static.h
index 9222a8c8..b63fbba0 100644
--- a/lib/zstd_static.h
+++ b/lib/zstd_static.h
@@ -59,7 +59,14 @@ size_t      ZSTD_freeDCtx(ZSTD_dctx_t dctx);
 
 size_t ZSTD_nextSrcSizeToDecompress(ZSTD_dctx_t dctx);
 size_t ZSTD_decompressContinue(ZSTD_dctx_t dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize);
-
+/*
+  Use above functions alternatively.
+  ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as input to ZSTD_decompressContinue().
+  This value is expected to be provided, precisely, as 'srcSize'.
+  Otherwise, compression will fail (result is an error code, which can be tested using ZSTD_isError() )
+  ZSTD_decompressContinue() result is the number of bytes regenerated within 'dst'.
+  It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
+*/
 
 /**************************************
 *  Error management