Clarify behavior of GetWindowTextLength towards zero-length titles

sdk-api-src/content/winuser/nf-winuser-getwindowtextlengtha.md

@@ -73,22 +73,19 @@ A handle to the window or control.
 
 ## -returns
 
+Type: <b>int</b>
 
+If the function succeeds, the return value is the length, in characters, of the text. Under certain conditions, this value might be greater than the length of the text (see Remarks).
 
-Type: <strong>Type: <b>int</b>
-</strong>
-
-If the function succeeds, the return value is the length, in characters, of the text. Under certain conditions, this value may actually be greater than the length of the text. For more information, see the following Remarks section.
-
-If the window has no text, the return value is zero. To get extended error information, call <a href="https://docs.microsoft.com/windows/desktop/api/errhandlingapi/nf-errhandlingapi-getlasterror">GetLastError</a>. 
-
+If the window has no text, the return value is zero. 
 
+Function failure is indicated by a return value of zero and a <a href="https://docs.microsoft.com/windows/desktop/api/errhandlingapi/nf-errhandlingapi-getlasterror">GetLastError</a> result that is nonzero.
 
+> [!NOTE]
+> This function does not clear the most recent error information. To determine success or failure, clear the most recent error information by calling <a href="https://docs.microsoft.com/windows/desktop/api/errhandlingapi/nf-errhandlingapi-setlasterror">SetLastError</a> with 0, then call <a href="https://docs.microsoft.com/windows/desktop/api/errhandlingapi/nf-errhandlingapi-getlasterror">GetLastError</a>. 
 
 ## -remarks
 
-
-
 If the target window is owned by the current process, <b>GetWindowTextLength</b> causes a <a href="https://docs.microsoft.com/windows/desktop/winmsg/wm-gettextlength">WM_GETTEXTLENGTH</a> message to be sent to the specified window or control. 
 
 Under certain conditions, the <b>GetWindowTextLength</b> function may return a value that is larger than the actual length of the text. This occurs with certain mixtures of ANSI and Unicode, and is due to the system allowing for the possible existence of double-byte character set (DBCS) characters within the text. The return value, however, will always be at least as large as the actual length of the text; you can thus always use it to guide buffer allocation. This behavior can occur when an application uses both ANSI functions and common dialogs, which use Unicode. It can also occur when an application uses the ANSI version of <b>GetWindowTextLength</b> with a window whose window procedure is Unicode, or the Unicode version of <b>GetWindowTextLength</b> with a window whose window procedure is ANSI. For more information on ANSI and ANSI functions, see <a href="https://docs.microsoft.com/windows/desktop/Intl/conventions-for-function-prototypes">Conventions for Function Prototypes</a>. 

sdk-api-src/content/winuser/nf-winuser-getwindowtextlengthw.md

@@ -73,22 +73,19 @@ A handle to the window or control.
 
 ## -returns
 
+Type: <b>int</b>
 
+If the function succeeds, the return value is the length, in characters, of the text. Under certain conditions, this value might be greater than the length of the text (see Remarks).
 
-Type: <strong>Type: <b>int</b>
-</strong>
-
-If the function succeeds, the return value is the length, in characters, of the text. Under certain conditions, this value may actually be greater than the length of the text. For more information, see the following Remarks section.
-
-If the window has no text, the return value is zero. To get extended error information, call <a href="https://docs.microsoft.com/windows/desktop/api/errhandlingapi/nf-errhandlingapi-getlasterror">GetLastError</a>. 
-
+If the window has no text, the return value is zero. 
 
+Function failure is indicated by a return value of zero and a <a href="https://docs.microsoft.com/windows/desktop/api/errhandlingapi/nf-errhandlingapi-getlasterror">GetLastError</a> result that is nonzero.
 
+> [!NOTE]
+> This function does not clear the most recent error information. To determine success or failure, clear the most recent error information by calling <a href="https://docs.microsoft.com/windows/desktop/api/errhandlingapi/nf-errhandlingapi-setlasterror">SetLastError</a> with 0, then call <a href="https://docs.microsoft.com/windows/desktop/api/errhandlingapi/nf-errhandlingapi-getlasterror">GetLastError</a>. 
 
 ## -remarks
 
-
-
 If the target window is owned by the current process, <b>GetWindowTextLength</b> causes a <a href="https://docs.microsoft.com/windows/desktop/winmsg/wm-gettextlength">WM_GETTEXTLENGTH</a> message to be sent to the specified window or control. 
 
 Under certain conditions, the <b>GetWindowTextLength</b> function may return a value that is larger than the actual length of the text. This occurs with certain mixtures of ANSI and Unicode, and is due to the system allowing for the possible existence of double-byte character set (DBCS) characters within the text. The return value, however, will always be at least as large as the actual length of the text; you can thus always use it to guide buffer allocation. This behavior can occur when an application uses both ANSI functions and common dialogs, which use Unicode. It can also occur when an application uses the ANSI version of <b>GetWindowTextLength</b> with a window whose window procedure is Unicode, or the Unicode version of <b>GetWindowTextLength</b> with a window whose window procedure is ANSI. For more information on ANSI and ANSI functions, see <a href="https://docs.microsoft.com/windows/desktop/Intl/conventions-for-function-prototypes">Conventions for Function Prototypes</a>.