How to insert REL ALTERNATE ?

Hello,

For now, the user lands on the desktop version, on which there is a button link pointing toward the mobile version.
It would be a lot better if it could be automatic (the browser detects the screen size and serve the right version upon this criteria), but sincerely, I really don't know how to perform this.
At least, I would like the source code to indicat the right canonical URL, but I still wonder where I am supposed to insert the PHP above...

Thank you.

Hello

if your content is a FLEXIcontent item , then you can use 2 FLEXIcontent item layouts (template) for every content type
- 1 item layout (of a FLEXIcontent template) for desktop
- 1 item layout (of a FLEXIcontent template) for mobile (you can choose if "Tablets" will be servered the desktop or the mobile layout)

- Go to FLEXIcontent component parameters (configuration button)
and enable mobile layouts
- then go edit the content type (in backend "Types") and you can select a different layout for mobile users
- then go edit the item layout (FLEXIcontent template) that you selected and add your fields or also edit and customize the HTML
item.php
item_html5.php

Oh, OK, thank you. Maybe it will be useful for some other time, but not for this one:
All my items are Flexicontent items, but for those pages, the trouble is coming from a gallery.
The layout has to be different depending on screen size. So I cannot change it just by changing the FC template.
(I use sigplus gallery)
That's why I was looking for the rel alternate tag (plus, if possible, a way to direct automaticaly the user to the right url depending on his display size, but I feel this is going to be a bit difficult for me)

Hello

-- about add REL alternate you can do like i said above,

-- but about showing 2 different items depending on the user's browser / device
how do you do it ?
are you using some extension ?
i mean if it is different visitor language Joomla will switch to the associated translation item, and add an appropriate REL

Hello

please see my answer above

also why are you using Joomla 3.3.6 with FC v2.0
both are outdated