1 files changed, 12 insertions, 9 deletions

diff --git a/manual/manual.of b/manual/manual.of
index c69970d2..2a837b5e 100644
--- a/manual/manual.of
+++ b/manual/manual.of
@@ -5915,6 +5915,9 @@ previously pushed on the stack
 on top of the library table.
 These values are popped from the stack after the registration.
 
+A function with a @id{NULL} value represents a placeholder,
+which is filled with @false.
+
 }
 
 @APIEntry{void luaL_setmetatable (lua_State *L, const char *tname);|
@@ -6397,7 +6400,7 @@ This means that any error @N{inside @T{f}} is not propagated;
 instead, @id{pcall} catches the error
 and returns a status code.
 Its first result is the status code (a boolean),
-which is true if the call succeeds without errors.
+which is @true if the call succeeds without errors.
 In such case, @id{pcall} also returns all results from the call,
 after this first result.
 In case of any error, @id{pcall} returns @false plus the error object.
@@ -6603,7 +6606,7 @@ an object with type @T{"thread"}.
 
 @LibEntry{coroutine.isyieldable ([co])|
 
-Returns true when the coroutine @id{co} can yield.
+Returns @true when the coroutine @id{co} can yield.
 The default for @id{co} is the running coroutine.
 
 A coroutine is yieldable if it is not the main thread and
@@ -6635,7 +6638,7 @@ If there is any error,
 @LibEntry{coroutine.running ()|
 
 Returns the running coroutine plus a boolean,
-true when the running coroutine is the main one.
+@true when the running coroutine is the main one.
 
 }
 
@@ -6730,7 +6733,7 @@ If the loader returns any non-nil value,
 @id{require} assigns the returned value to @T{package.loaded[modname]}.
 If the loader does not return a non-nil value and
 has not assigned any value to @T{package.loaded[modname]},
-then @id{require} assigns @Rw{true} to this entry.
+then @id{require} assigns @true to this entry.
 In any case, @id{require} returns the
 final value of @T{package.loaded[modname]}.
 Besides that value, @id{require} also returns as a second result
@@ -7051,7 +7054,7 @@ otherwise, it returns @fail.
 A third, optional numeric argument @id{init} specifies
 where to start the search;
 its default value @N{is 1} and can be negative.
-A value of @true as a fourth, optional argument @id{plain}
+A @true as a fourth, optional argument @id{plain}
 turns off the pattern matching facilities,
 so the function does a plain @Q{find substring} operation,
 with no characters in @id{pattern} being considered magic.
@@ -8077,7 +8080,7 @@ or @fail if @id{x} is not a number.
 @LibEntry{math.ult (m, n)|
 
 Returns a boolean,
-true if and only if integer @id{m} is below integer @id{n} when
+@true if and only if integer @id{m} is below integer @id{n} when
 they are compared as @x{unsigned integers}.
 
 }
@@ -8490,13 +8493,13 @@ When called without a @id{command},
 @LibEntry{os.exit ([code [, close]])|
 
 Calls the @ANSI{exit} to terminate the host program.
-If @id{code} is @Rw{true},
+If @id{code} is @true,
 the returned status is @idx{EXIT_SUCCESS};
-if @id{code} is @Rw{false},
+if @id{code} is @false,
 the returned status is @idx{EXIT_FAILURE};
 if @id{code} is a number,
 the returned status is this number.
-The default value for @id{code} is @Rw{true}.
+The default value for @id{code} is @true.
 
 If the optional second argument @id{close} is true,
 closes the Lua state before exiting.