Canon MF211 Manual page 242

<Adjustment/Maintenance>
<Copy> or <Print>
After the setting is enabled
When set to <On>, this setting takes priority over the setting for <Special Mode Z>.
While more effect is gained than with <Special Mode Z>, print speed is slower.
After printing from a smartphone or tablet
If streaks adhere to the paper, change the setting with <Special Mode D>
Special Mode I
Only select <On> if paper jams frequently when printing on lightweight paper or on curled paper.
Off
On
<Adjustment/Maintenance>
When set to <On>
White patches may appear in images printed on paper other than lightweight paper.
Special Mode J
If printing is uneven when printing fine lines or faint images, select <On>.
Off
On
<Adjustment/Maintenance>
When set to <On>.
The following may occur.
Definition may be affected
Toner appears in non-print areas when using a new toner cartridge
Toner may be used up more quickly
<Special Processing>
<On>
<Special Processing>
<Special Processing>
<Special Mode D>
<Copy>.
<Special Mode I>
<Special Mode J>
Select
<On>
<On>