refine documentation on how to use the flag

Author: malpou

docs/flags.md

@@ -150,6 +150,7 @@
 | `--txt-prefix=""` | When using the TXT registry, a custom string that's prefixed to each ownership DNS record (optional). Could contain record type template like '%{record_type}-prefix-'. Mutual exclusive with txt-suffix! |
 | `--txt-suffix=""` | When using the TXT registry, a custom string that's suffixed to the host portion of each ownership DNS record (optional). Could contain record type template like '-%{record_type}-suffix'. Mutual exclusive with txt-prefix! |
 | `--txt-wildcard-replacement=""` | When using the TXT registry, a custom string that's used instead of an asterisk for TXT records corresponding to wildcard DNS records (optional) |
+| `--txt-new-format-only` | When using the TXT registry, only create new format records with record type information (default: disabled) |
 | `--[no-]txt-encrypt-enabled` | When using the TXT registry, set if TXT records should be encrypted before stored (default: disabled) |
 | `--txt-encrypt-aes-key=""` | When using the TXT registry, set TXT record decryption and encryption 32 byte aes key (required when --txt-encrypt=true) |
 | `--dynamodb-region=""` | When using the DynamoDB registry, the AWS region of the DynamoDB table (optional) |

docs/registry/txt.md

@@ -10,16 +10,19 @@ The TXT registry supports two formats for storing DNS record metadata:
 
 By default, the TXT registry creates records in both formats for backwards compatibility. You can configure it to use only the new format by using the `--txt-new-format-only` flag. This reduces the number of TXT records created, which can be helpful when working with provider-specific record limits.
 
-Note: AAAA records always use only the new format regardless of this setting.
+Note: The following record types always use only the new format regardless of this setting:
+- AAAA records
+- Encrypted TXT records (when using `--txt-encrypt-enabled`)
 
 Example:
 ```sh
 # Default behavior - creates both formats
-external-dns
+external-dns --provider=aws --source=ingress --managed-record-types=A,TXT
 
-# Only create new format records
-external-dns --txt-new-format-only
+# Only create new format records (alongside other required flags)
+external-dns --provider=aws --source=ingress --managed-record-types=A,TXT --txt-new-format-only
 ```
+The `--txt-new-format-only` flag should be used in addition to your existing external-dns configuration flags. It does not implicitly configure TXT record handling - you still need to specify `--managed-record-types=TXT` if you want external-dns to manage TXT records.
 
 ## Prefixes and Suffixes