Miscellaneous constructs either modify a regular expression pattern or provide information about it. The following table lists the miscellaneous constructs supported by the .NET Framework.
| Pattern | Description | Example |
| (?imnsx-imnsx) | Sets or disables options such as case insensitivity in the middle of a pattern. | \bA(?i)b\w+\b matches "ABA", "Able" in "ABA Able Act" |
| (?# comment) | Inline comment. The comment ends at the first closing parenthesis. | \bA(?#Matches words starting with A)\w+\b |
| #[to end of line] | X-mode comment. The comment starts at an unescaped # and continues to the end of the line. | (?x)\bA\w+\b#Matches words starting with A |