diff --git a/docs/grammar/README.md b/docs/grammar/README.md
index 4522f663a9..5a9d1a6850 100644
--- a/docs/grammar/README.md
+++ b/docs/grammar/README.md
@@ -21,11 +21,26 @@ along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
 Lexical Grammar
 ---------------
 
+<a name="ascii"></a>
+```abnf
+ascii = %x0-7F
+```
+
+<a name="safe-nonascii"></a>
+```abnf
+safe-nonascii = %x80-2029 / %x202F-2065 / %x2070-D7FF / %xE000-10FFFF
+                ; excludes bidi overrides and high/low surrogates
+```
+
 <a name="character"></a>
 ```abnf
-character = %x0-D7FF / %xE000-10FFFF   ; Unicode code points decoded from UTF-8
+character = ascii / safe-nonascii
+            ; Unicode code points decoded from UTF-8
 ```
 
+Go to: _[ascii](#user-content-ascii), [safe-nonascii](#user-content-safe-nonascii)_;
+
+
 <a name="horizontal-tab"></a>
 ```abnf
 horizontal-tab = %x9   ; <HT>
@@ -58,33 +73,48 @@ single-quote = %x27   ; '
 
 <a name="not-star"></a>
 ```abnf
-not-star = %x0-29 / %x2B-D7FF / %xE000-10FFFF   ; anything but *
+not-star = %x0-29 / %x2B-7F / safe-nonascii  ; anything but *
 ```
 
+Go to: _[safe-nonascii](#user-content-safe-nonascii)_;
+
+
 <a name="not-star-or-slash"></a>
 ```abnf
-not-star-or-slash = %x0-29 / %x2B-2E / %x30-D7FF / %xE000-10FFFF
+not-star-or-slash = %x0-29 / %x2B-2E / %x30-7F / safe-nonascii
                     ; anything but * or /
 ```
 
+Go to: _[safe-nonascii](#user-content-safe-nonascii)_;
+
+
 <a name="not-line-feed-or-carriage-return"></a>
 ```abnf
-not-line-feed-or-carriage-return = %x0-9 / %xB-C / %xE-D7FF / %xE000-10FFFF
+not-line-feed-or-carriage-return = %x0-9 / %xB-C / %xE-7F / safe-nonascii
                                    ; anything but <LF> or <CR>
 ```
 
+Go to: _[safe-nonascii](#user-content-safe-nonascii)_;
+
+
 <a name="not-double-quote-or-backslash"></a>
 ```abnf
-not-double-quote-or-backslash = %x0-21 / %x23-5B / %x5D-D7FF / %xE000-10FFFF
+not-double-quote-or-backslash = %x0-21 / %x23-5B / %x5D-7F / safe-nonascii
                                 ; anything but " or \
 ```
 
+Go to: _[safe-nonascii](#user-content-safe-nonascii)_;
+
+
 <a name="not-single-quote-or-backslash"></a>
 ```abnf
-not-single-quote-or-backslash = %x0-26 / %x28-5B / %x5D-D7FF / %xE000-10FFFF
+not-single-quote-or-backslash = %x0-26 / %x28-5B / %x5D-7F / safe-nonascii
                                 ; anything but ' or \
 ```
 
+Go to: _[safe-nonascii](#user-content-safe-nonascii)_;
+
+
 <a name="line-terminator"></a>
 ```abnf
 line-terminator = line-feed / carriage-return / carriage-return line-feed
@@ -148,6 +178,7 @@ keyword = %s"address"
         / %s"char"
         / %s"console"
         / %s"const"
+        / %s"constant"
         / %s"else"
         / %s"field"
         / %s"for"
@@ -236,6 +267,15 @@ signed-literal = numeral ( %s"i8" / %s"i16" / %s"i32" / %s"i64" / %s"i128" )
 Go to: _[numeral](#user-content-numeral)_;
 
 
+<a name="integer-literal"></a>
+```abnf
+integer-literal = unsigned-literal
+                / signed-literal
+```
+
+Go to: _[signed-literal](#user-content-signed-literal), [unsigned-literal](#user-content-unsigned-literal)_;
+
+
 <a name="field-literal"></a>
 ```abnf
 field-literal = numeral %s"field"
@@ -368,15 +408,6 @@ string-literal-element = not-double-quote-or-backslash
 Go to: _[ascii-character-escape](#user-content-ascii-character-escape), [not-double-quote-or-backslash](#user-content-not-double-quote-or-backslash), [simple-character-escape](#user-content-simple-character-escape), [unicode-character-escape](#user-content-unicode-character-escape)_;
 
 
-<a name="integer-literal"></a>
-```abnf
-integer-literal = unsigned-literal
-                / signed-literal
-```
-
-Go to: _[signed-literal](#user-content-signed-literal), [unsigned-literal](#user-content-unsigned-literal)_;
-
-
 <a name="atomic-literal"></a>
 ```abnf
 atomic-literal = integer-literal
@@ -805,7 +836,7 @@ Go to: _[function-parameter](#user-content-function-parameter)_;
 
 <a name="function-parameter"></a>
 ```abnf
-function-parameter = [ %s"public" / %s"const" ] identifier ":" type
+function-parameter = [ %s"public" / %s"constant" / %s"const" ] identifier ":" type
 ```
 
 Go to: _[identifier](#user-content-identifier), [type](#user-content-type)_;
diff --git a/docs/grammar/abnf-grammar.txt b/docs/grammar/abnf-grammar.txt
index 5b91993063..f783304d26 100644
--- a/docs/grammar/abnf-grammar.txt
+++ b/docs/grammar/abnf-grammar.txt
@@ -19,7 +19,13 @@
 ; Lexical Grammar
 ; ---------------
 
-character = %x0-D7FF / %xE000-10FFFF   ; Unicode code points decoded from UTF-8
+ascii = %x0-7F
+
+safe-nonascii = %x80-2029 / %x202F-2065 / %x2070-D7FF / %xE000-10FFFF
+                ; excludes bidi overrides and high/low surrogates
+
+character = ascii / safe-nonascii
+            ; Unicode code points decoded from UTF-8
 
 horizontal-tab = %x9   ; <HT>
 
@@ -33,18 +39,18 @@ double-quote = %x22   ; "
 
 single-quote = %x27   ; '
 
-not-star = %x0-29 / %x2B-D7FF / %xE000-10FFFF   ; anything but *
+not-star = %x0-29 / %x2B-7F / safe-nonascii  ; anything but *
 
-not-star-or-slash = %x0-29 / %x2B-2E / %x30-D7FF / %xE000-10FFFF
+not-star-or-slash = %x0-29 / %x2B-2E / %x30-7F / safe-nonascii
                     ; anything but * or /
 
-not-line-feed-or-carriage-return = %x0-9 / %xB-C / %xE-D7FF / %xE000-10FFFF
+not-line-feed-or-carriage-return = %x0-9 / %xB-C / %xE-7F / safe-nonascii
                                    ; anything but <LF> or <CR>
 
-not-double-quote-or-backslash = %x0-21 / %x23-5B / %x5D-D7FF / %xE000-10FFFF
+not-double-quote-or-backslash = %x0-21 / %x23-5B / %x5D-7F / safe-nonascii
                                 ; anything but " or \
 
-not-single-quote-or-backslash = %x0-26 / %x28-5B / %x5D-D7FF / %xE000-10FFFF
+not-single-quote-or-backslash = %x0-26 / %x28-5B / %x5D-7F / safe-nonascii
                                 ; anything but ' or \
 
 line-terminator = line-feed / carriage-return / carriage-return line-feed
@@ -112,6 +118,9 @@ unsigned-literal = numeral ( %s"u8" / %s"u16" / %s"u32" / %s"u64" / %s"u128" )
 
 signed-literal = numeral ( %s"i8" / %s"i16" / %s"i32" / %s"i64" / %s"i128" )
 
+integer-literal = unsigned-literal
+                / signed-literal
+
 field-literal = numeral %s"field"
 
 product-group-literal = numeral %s"group"
@@ -160,9 +169,6 @@ string-literal-element = not-double-quote-or-backslash
                        / ascii-character-escape
                        / unicode-character-escape
 
-integer-literal = unsigned-literal
-                / signed-literal
-
 atomic-literal = integer-literal
                / field-literal
                / product-group-literal