1title: Legacy EM Extension 2 3# Legacy EM 4 5## Summary 6 7The Legacy EM extension restores Markdown's original behavior for emphasis and 8strong syntax when using underscores. 9 10By default Python-Markdown treats `_connected_words_` intelligently by 11recognizing that mid-word underscores should not be used for emphasis. In other 12words, by default, that input would result in this output: 13`<em>connected_words</em>`. 14 15However, that behavior is not consistent with the original rules or the behavior 16of the reference implementation. Therefore, this extension can be used to better 17match the reference implementation. With the extension enabled, the above input 18would result in this output: `<em>connected</em>words_`. 19 20## Usage 21 22See [Extensions](index.md) for general extension usage. Use `legacy_em` as the 23name of the extension. 24 25This extension does not accept any special configuration options. 26 27A trivial example: 28 29```python 30markdown.markdown(some_text, extensions=['legacy_em']) 31``` 32