diff --git a/00.brainstorming-pedagogical-teams/45.synthesis-structuring/30.classical-mechanics/05.first-steps/textbook.en.md b/00.brainstorming-pedagogical-teams/45.synthesis-structuring/30.classical-mechanics/05.first-steps/textbook.en.md
index c5fd54e8e..32dde460e 100644
--- a/00.brainstorming-pedagogical-teams/45.synthesis-structuring/30.classical-mechanics/05.first-steps/textbook.en.md
+++ b/00.brainstorming-pedagogical-teams/45.synthesis-structuring/30.classical-mechanics/05.first-steps/textbook.en.md
@@ -43,7 +43,7 @@ _(BRST-MECCLAS1 pour Brainstorming STructure MEChanics CLASsical level 1)_
 
 To **add an item, create it** in or after existing items (following the logical order).
 To do this, start your proposition with a new : <br>
-* *[BRST-MECACLAS1-number] + (three initials in brackets representing you) + Title*
+* *[BRST-MECCLAS1-number] + (three initials in brackets representing you) + Title*
 
 To **react to an existing item*, add your comment after the others
 starting with three initials in brackets that represent you :