diff --git a/README b/README
index 055026aea..46ddd8464 100644
--- a/README
+++ b/README
@@ -18,7 +18,7 @@ Along with the game improvements and bug fixes, NetHack 5.0 strives to make
 some general architectural improvements to the game or to its building
 process. Among them, 5.0 has:
 
- *  The source code is standard C99.
+ *  The source code is compliant with the C99 standard.
 
  *  removes barriers to building NetHack on one platform and operating system,
     for later execution on another (possibly quite different) platform and/or
diff --git a/doc/Guidebook.mn b/doc/Guidebook.mn
index b32144a6d..60a993cd5 100644
--- a/doc/Guidebook.mn
+++ b/doc/Guidebook.mn
@@ -6820,7 +6820,7 @@ been released as version 4.0.
 NetHack 5.0.0 was released on May 2, 2026.
 .pg
 The source code for NetHack 5.0.0 was modified and modernized to be
-compliant with standard C99. The 5.0.0 release contained over 3100 fixes,
+compliant with the C99 standard. The 5.0.0 release contained over 3100 fixes,
 changes, and updated features.
 .pg
 NetHack 5.0 was the first version to replace the lex and yacc level
diff --git a/doc/Guidebook.tex b/doc/Guidebook.tex
index 20bd1fcaa..e0c1e43c5 100644
--- a/doc/Guidebook.tex
+++ b/doc/Guidebook.tex
@@ -7578,7 +7578,7 @@ been released as version 4.0.
 %.pg
 \medskip
 The source code for \textit{NetHack} 5.0.0 was modified and modernized to be
-compliant with standard C99. The 5.0.0 release contained over 3100 fixes,
+compliant with the C99 standard. The 5.0.0 release contained over 3100 fixes,
 changes, and updated features.
 
 %.pg
diff --git a/include/patchlevel.h b/include/patchlevel.h
index f2c1a667d..599e7270d 100644
--- a/include/patchlevel.h
+++ b/include/patchlevel.h
@@ -67,7 +67,7 @@
 /*
  *  NetHack 5.0.0, May 2, 2026
  *
- *  Sources changed to C99.
+ *  Sources changed to be compliant with the C99 standard.
  *  level compiler, dungeon compiler, and quest text all replaced with
  *    Lua alternatives.
  *  Refer to doc/fixes5-0-0.txt for a complete list of fixes and changes.