update style guide

1 files changed, 1 insertions, 0 deletions

diff --git a/style.md b/style.md
index 3fe912b..db3e1d7 100644
--- a/style.md
+++ b/style.md
@@ -31,6 +31,7 @@ before formatting as a failsafe.
 - library hooks that need specific symbol names are exempt from the naming
   conventions (e.g. `main` or `HAL_UART_MspInit`)
 - names are always in English
+- filenames should not be prefixed by anything.
 
 ## others