The image file will be searched for using the same rules as used to find
the file pointed to by a [[ikiwiki/WikiLink]].
-The `size` parameter is optional, defaulting to full size. Note that the
-original image's aspect ratio is always preserved, even if this means
-making the image smaller than the specified size. You can also specify only
-the width or the height, and the other value will be calculated based on
-it: "200x", "x200"
+The `size` parameter is optional, defaulting to full size.
+You can specify only the width or the height, and the other value will
+be calculated based on it: "200x", "x200".
+
+If you specify both the width and height, the original image's aspect
+ratio will be preserved, even if this means making the image smaller
+than the specified size. (However, this is not done for svg images.)
You can also pass `alt`, `title`, `class`, `align`, `id`, `hspace`, and
`vspace` parameters.
\[[!img photo2.jpg]]
\[[!img photo3.jpg size=200x600]]
+## format support
+
+By default, the `img` directive only supports a few common web formats:
+
+* PNG (`.png`)
+* JPEG (`.jpg` or `.jpeg`)
+* GIF (`.gif`)
+* SVG (`.svg`)
+
+These additional formats can be enabled with the `img_allowed_formats`
+[[!iki setup]] option, but are disabled by default for better
+[[!iki security]]:
+
+* PDF (`.pdf`)
+* `everything` (accepts any file supported by ImageMagick: make sure
+ that only completely trusted users can
+ [[upload attachments|ikiwiki/pagespec/attachment]])
+
+For example, a wiki where only `admin()` users can upload attachments might
+use:
+
+ img_allowed_formats: [png, jpeg, gif, svg, pdf]
+
[[!meta robots="noindex, follow"]]