Standardize 'null' to 'NULL'

Author: TylerMSFT

docs/c-runtime-library/reference/vsnprintf-s-vsnprintf-s-vsnprintf-s-l-vsnwprintf-s-vsnwprintf-s-l.md

@@ -105,9 +105,9 @@ See [Behavior summary](#behavior-summary) for details.
 
 ## Remarks
 
-Each of these functions takes a pointer to an argument list, then formats and writes up to *`count`* characters of the given data to the memory pointed to by *`buffer`* and appends a terminating null.
+Each of these functions takes a pointer to an argument list, then formats and writes up to *`count`* characters of the given data to the memory pointed to by *`buffer`* and appends a terminating `NULL`.
 
-In debug builds, the remaining `sizeOfBuffer` bytes following the terminating NULL are filled with 'xFE' as described in [`_CrtSetDebugFillThreshold`](crtsetdebugfillthreshold.md).
+In debug builds, the remaining `sizeOfBuffer` bytes following the terminating `NULL` are filled with 'xFE' as described in [`_CrtSetDebugFillThreshold`](crtsetdebugfillthreshold.md).
 
 The versions of these functions with the **`_l`** suffix are identical except that they use the locale parameter passed in instead of the current thread locale.
 
@@ -129,7 +129,7 @@ For the following table:
 | `buffer == NULL` and `sizeOfBuffer == 0` and `count == 0` | No data is written. | 0 | N/A | No |
 | `buffer == NULL` and either `sizeOfBuffer != 0` or `count != 0` | If execution continues after invalid parameter handler executes, sets `errno` and returns a negative value.| -1 | `EINVAL` (22) | Yes |
 | `buffer != NULL` and `sizeOfBuffer == 0` | No data is written. If execution continues after invalid parameter handler executes, sets `errno` and returns a negative value. | -1 | `EINVAL` (22) | Yes |
-| `buffer != NULL` and `sizeOfBuffer != 0` and `count == 0` | The buffer is NULL terminated. | -1 | N/A | No |
+| `buffer != NULL` and `sizeOfBuffer != 0` and `count == 0` | The buffer is `NULL` terminated. | -1 | N/A | No |
 | `count == 0`| Doesn't write any data and returns the number of characters that would have been written, not including the terminating `NULL`. | The number of characters that would have been written not including the terminating `NULL`. | N/A | No |
 | `count < 0` | Unsafe: the value is treated as unsigned, likely creating a large value that results in overwriting the memory that follows the buffer. | The number of characters written, not including the terminating `NULL`. | N/A | No |
 | `count < sizeOfBuffer` and `len <= count`  | All of the data is written and a terminating `NULL` is appended. | The number of characters written. | N/A | No |
@@ -147,7 +147,7 @@ For information about these and other error codes, see [`_doserrno`, `errno`, `_
 > Starting in Windows 10 version 2004 (build 19041), the `printf` family of functions prints exactly representable floating point numbers according to the IEEE 754 rules for rounding. In previous versions of Windows, exactly representable floating point numbers ending in '5' would always round up. IEEE 754 states that they must round to the closest even digit (also known as "Banker's Rounding"). For example, both `printf("%1.0f", 1.5)` and `printf("%1.0f", 2.5)` should round to 2. Previously, 1.5 would round to 2 and 2.5 would round to 3. This change only affects exactly representable numbers. For example, 2.35 (which, when represented in memory, is closer to 2.35000000000000008) continues to round up to 2.4. Rounding done by these functions now also respects the floating point rounding mode set by [`fesetround`](fegetround-fesetround2.md). Previously, rounding always chose `FE_TONEAREST` behavior. This change only affects programs built using Visual Studio 2019 version 16.2 and later. To use the legacy floating point rounding behavior, link with ['legacy_stdio_float_rounding.obj`](../link-options.md).
 
 > [!NOTE]
-> To ensure that there is room for the terminating null, be sure that *`count`* is strictly less than the buffer length, or use `_TRUNCATE`.
+> To ensure that there is room for the terminating `NULL`, be sure that *`count`* is strictly less than the buffer length, or use `_TRUNCATE`.
 
 In C++, using these functions is simplified by template overloads; the overloads can infer buffer length automatically (eliminating the need to specify a size argument) and they can automatically replace older, non-secure functions with their newer, secure counterparts. For more information, see [Secure template overloads](../secure-template-overloads.md).