diff --git a/README.md b/README.md
index 4b658c471..9d2bdc641 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,8 @@ Includes a [relinker](core/relinker) that converts executable to the target syst
 
 [![progress map](https://boykopovar.github.io/AnyPS5/progress.svg)](https://boykopovar.github.io/AnyPS5/)
 
+<sub>* System libraries: percentage of the functions known to the project so far (declared in [core/libs/prx](core/libs/prx)), not of every PS5 system function. The total grows as more functions are declared.</sub>
+
 [List of verified games](docs/user/COMPATIBILITY.md)
 
 Dreaming Sarah (2D platformer) runs at a stable 60 fps on a GTX 1050 Ti / i5-7500 3.4GHz.