diff --git a/OPTIONS.md b/OPTIONS.md
index 0382c6d7fc..642d9549fc 100644
--- a/OPTIONS.md
+++ b/OPTIONS.md
@@ -8,20 +8,19 @@
  - See the COPYRIGHT file distributed with this work for additional
  - information regarding copyright ownership.
 -->
-Setting the `STD_CDEFINES` environment variable before running `configure`
-can be used to enable certain compile-time options that are not explicitly
-defined in `configure`.
+Setting the `CPPFLAGS` environment variable before running `configure`
+can be used to enable certain compile-time options that are not
+explicitly defined in `configure`.
 
 Some of these settings are:
 
-|Setting                            |Description |
-|-----------------------------------|----------------------------------------|
-|`-DISC_MEM_DEFAULTFILL=1`|Overwrite memory with tag values when allocating or freeing it; this impairs performance but makes debugging of memory problems easier.|
-|`-DISC_MEM_TRACKLINES=0`|Don't track memory allocations by file and line number; this improves performance but makes debugging more difficult.|
-|<nobr>`-DISC_FACILITY=LOG_LOCAL0`</nobr>|Change the default syslog facility for `named`|
-|`-DNS_CLIENT_DROPPORT=0`|Disable dropping queries from particular well-known ports:|
-|`-DCHECK_SIBLING=0`|Don't check sibling glue in `named-checkzone`|
-|`-DCHECK_LOCAL=0`|Don't check out-of-zone addresses in `named-checkzone`|
-|`-DNS_RUN_PID_DIR=0`|Create default PID files in `${localstatedir}/run` rather than `${localstatedir}/run/named/`|
-|`-DISC_BUFFER_USEINLINE=0`|Disable the use of inline functions to implement the `isc_buffer` API: this reduces performance but may be useful when debugging |
-|`-DISC_HEAP_CHECK`|Test heap consistency after every heap operation; used when debugging|
+| Setting                      | Description                                                                                                                            |
+| ---------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- |
+| `-DCHECK_LOCAL=0`            | Don't check out-of-zone addresses in `named-checkzone`                                                                                 |
+| `-DCHECK_SIBLING=0`          | Don't check sibling glue in `named-checkzone`                                                                                          |
+| `-DISC_FACILITY=LOG_LOCAL0`  | Change the default syslog facility for `named`                                                                                         |
+| `-DISC_HEAP_CHECK`           | Test heap consistency after every heap operation; used when debugging                                                                  |
+| `-DISC_MEM_DEFAULTFILL=1`    | Overwrite memory with tag values when allocating or freeing it; this impairs performance but makes debugging of memory problems easier |
+| `-DISC_MEM_TRACKLINES=0`     | Don't track memory allocations by file and line number; this improves performance but makes debugging more difficult                   |
+| `-DNAMED_RUN_PID_DIR=0`      | Create default PID files in `${localstatedir}/run` rather than `${localstatedir}/run/named/`                                           |
+| `-DNS_CLIENT_DROPPORT=0`     | Disable dropping queries from particular well-known ports                                                                              |