Flag	Default	Blackfriday flag
`taskLists`	`true`
Purpose: `false` turns off GitHub-style automatic task/TODO list generation.
`smartypants`	`true`	`HTML_USE_SMARTYPANTS`
Purpose: `false` disables smart punctuation substitutions including smart quotes, smart dashes, smart fractions, etc. If `true`, it may be fine-tuned with the `angledQuotes`, `fractions`, `smartDashes`, and `latexDashes` flags (see below).
`angledQuotes`	`false`	`HTML_SMARTYPANTS_ANGLED_QUOTES`
Purpose: `true` enables smart, angled double quotes. Example: `"Hugo"` renders to «Hugo» instead of “Hugo”.
`fractions`	`true`	`HTML_SMARTYPANTS_FRACTIONS`
Purpose: `false` disables smart fractions. Example: `5/12` renders to ⁵⁄₁₂ (`<sup>5</sup>&frasl;<sub>12</sub>`). Caveat: Even with `fractions = false`, Blackfriday still converts 1/2, 1/4 and 3/4 respectively to ½ (`½`), ¼ (`¼`) and ¾ (`¾`), but only these three.
`smartDashes`	`true`	`HTML_SMARTYPANTS_DASHES`
Purpose: `false` disables smart dashes; i.e., the conversion of multiple hyphens into en dash or em dash. If `true`, its behavior can be modified with the `latexDashes` flag below.
`latexDashes`	`true`	`HTML_SMARTYPANTS_LATEX_DASHES`
Purpose: `false` disables LaTeX-style smart dashes and selects conventional smart dashes. Assuming `smartDashes` (above): If `true`, `--` is translated into “–” (`–`), whereas `---` is translated into “—” (`—`). If `false`, `--` is translated into “—” (`—`), whereas a spaced single hyphen between two words is translated into an en dash—e.g., `12 June - 3 July` becomes `12 June – 3 July`.
`hrefTargetBlank`	`false`	`HTML_HREF_TARGET_BLANK`
Purpose: `true` opens external links in a new window or tab.
`plainIDAnchors`	`true`	`FootnoteAnchorPrefix` and `HeaderIDSuffix`
Purpose: `true` renders any header and footnote IDs without the document ID. Example: renders `#my-header` instead of `#my-header:bec3ed8ba720b9073ab75abcf3ba5d97`.
`extensions`	`[]`	`EXTENSION_*`
Purpose: Enable one or more of Blackfriday's Markdown extensions (if they aren't Hugo defaults). Example: Include `"hardLineBreak"` in the list to enable Blackfriday's `EXTENSION_HARD_LINE_BREAK`.
`extensionsmask`	`[]`	`EXTENSION_*`
Purpose: Disable one or more of Blackfriday's Markdown extensions (if they are Hugo defaults). Example: Include `"autoHeaderIds"` in the list to disable Blackfriday's `EXTENSION_AUTO_HEADER_IDS`.

For additional Blackfriday configuration for multilingual sites, see Taxonomies and Blackfriday in Multingual Mode.