Why use [[]] syntax sometimes get the italic font sometimes not?

[Zhe Lee]

As the title said I use [[]] syntax, but the word above is normal font, the below word is italic, why is this? 

[Mark S.]

Italics usually means that the tiddler inside the braces [[*]] does not exist.

[Eric Shulman]

On Saturday, June 6, 2020 at 6:09:23 PM UTC-7, Zhe Lee wrote:

As the title said I use [[]] syntax, but the word above is normal font, the below word is italic, why is this? 

As noted here: https://tiddlywiki.com/#Creating%20and%20editing%20tiddlers

You create a tiddler either by clicking the + button in the sidebar, or by clicking on a link to a missing tiddler. Links to missing tiddlers are shown in blue italics.

and here: https://tiddlywiki.com/#Using%20links%20to%20navigate%20between%20tiddlers, in reference to the sidebar tabs:

Missing lists any tiddlers that don't yet exist, but have been linked to from other tiddlers. This is helpful for finding tiddlers you planned to create, but never got around to.

Also take note of this setting: https://tiddlywiki.com/#tv-show-missing-links%20Variable, which says:

The tv-show-missing-links variable defines if missing links within the scope of the variable are rendered as links or not.
Globally, the variable is set within the PageTemplate and can be changed in the $:/ControlPanel under Settings - Show missing links to tiddlers
If tv-show-missing-links is set to no, missing links are rendered as plain text
If tv-show-missing-links is set to yes, missing links are rendered as wiki-links

enjoy,

-e