diff --git a/HACKING b/HACKING
index 65de9e3a..ace2c4c4 100644
--- a/HACKING
+++ b/HACKING
@@ -251,7 +251,7 @@ The following are followed by a length element, then a number of character code
 values (which should match with the length):
 
 META_MARK             (*MARK:xxxx)
-META_COMMIT_ARG       )*COMMIT:xxxx)
+META_COMMIT_ARG       (*COMMIT:xxxx)
 META_PRUNE_ARG        (*PRUNE:xxx)
 META_SKIP_ARG         (*SKIP:xxxx)
 META_THEN_ARG         (*THEN:xxxx)
diff --git a/src/pcre2_error.c b/src/pcre2_error.c
index 9e2e89d2..f7b9a676 100644
--- a/src/pcre2_error.c
+++ b/src/pcre2_error.c
@@ -291,9 +291,9 @@ static const unsigned char match_error_texts[] =
   "heap limit exceeded\0"
   "invalid syntax\0"
   /* 65 */
-  "internal error - duplicate substitution match\0"
+  "internal error: duplicate substitution match\0"
   "PCRE2_MATCH_INVALID_UTF is not supported for DFA matching\0"
-  "INTERNAL ERROR: invalid substring offset\0"
+  "internal error: invalid substring offset\0"
   "feature is not supported by the JIT compiler\0"
   "error performing replacement case transformation\0"
   /* 70 */
diff --git a/src/pcre2_intmodedep.h b/src/pcre2_intmodedep.h
index a04c0c8a..756c3b14 100644
--- a/src/pcre2_intmodedep.h
+++ b/src/pcre2_intmodedep.h
@@ -293,7 +293,7 @@ UTF support is omitted, we don't even define them. */
 
 #define HAS_EXTRALEN(c) HASUTF8EXTRALEN(c)
 
-/* Returns with the additional number of characters if IS_MULTICHAR(c) is TRUE.
+/* Returns with the additional number of characters if HAS_EXTRALEN(c) is TRUE.
 Otherwise it has an undefined behaviour. */
 
 #define GET_EXTRALEN(c) (PRIV(utf8_table4)[(c) & 0x3fu])
@@ -379,7 +379,7 @@ because almost all calls are already within a block of UTF-8 only code. */
 
 #define HAS_EXTRALEN(c) (((c) & 0xfc00u) == 0xd800u)
 
-/* Returns with the additional number of characters if IS_MULTICHAR(c) is TRUE.
+/* Returns with the additional number of characters if HAS_EXTRALEN(c) is TRUE.
 Otherwise it has an undefined behaviour. */
 
 #define GET_EXTRALEN(c) 1