Display PDF attachments of rich texts: When checked, a PDF inserted into an RTFD documents will display its first page. Unchecked, you will see a link and the PDF's filename.

Scale image attachments: Images added to rich text files and formatted notes are scaled to the current width of the view/edit pane.

Check spelling while typing: Spellcheck while you write.

Check grammar with spelling: Check grammar as well as spelling while you write.

Correct spelling automatically: Correct misspelled words automatically.

Smart quotes: Convert straight quotes ("inch marks") to typographer's quotes ("curly quotes") while you type.

Smart copy/paste: Insert or remove spaces before and after cut or pasted text.

Smart links: Detect web addresses and turn them into clickable links.

Smart dashes: Convert characters, e.g., two hyphens into a proper dash.

Data detectors: Detect dates, times or addresses in text, and show possible actions when the mouse cursor moves over them.

Text replacement: Use the system-wide text replacements when editing text.

Author: Enter your name. It will be used as default for metadata, e.g., for new rich text documents or PDF annotations.

Ruler Units: Select your personal preference for ruler units: centimeters, inches, points, or picas.

Plain Text: Select your preferred font. This is the font automatically used when you create new documents. Additionally, specify the background and text colors to suit your taste.

Rich Text & Note: Select your preferred fonts for new rich text formats. This is the font automatically used when you create new rich text documents or formatted notes. It is also the default used for rendered Markdown documents, if no default stylesheet is specified.

Full Screen: Select your preferred font for reading and editing plain text files in full screen mode. Rich text documents will display their user-specified fonts.

Background: Choose a background color for the full screen mode.

Text: Choose a text color for the full screen mode.

Width: Choose a width for displaying documents in full screen mode. This setting will apply wider or narrower left and right margins, based on a percentage of the screen width.