How to put Alt tag on text?

Just read the thread about "Alt" SEO.

How do you add an Alt tag to a text area?
Whe I right click the text area I have tabs:
Link, mouse over , placeholder and Image Which I all believe to be associated with teh object - true?

(Page, Website and Publish I believe have nothing to do with the object - true?)

So, do I put html in Image Caption (Alt text)?
If so, should I put all key works that are contained in the text into this box?

The reason for an Alt tag is to describe something that is not text. Bitmap images are not visible to search engines which is why they need an Alt tag. But text is by it's nature searchable.

From the "Alt" SEO thread I got the impression that even text objects in Xara are converted to images and therefore Google may not favor Xara sites, hence my question.
Did I misunderstand?

Just so as we don't get confused, alt is an attribute, not a tag. Some people get very annoyed about such things ... understandably [he says, ducking] :D

http://www.w3.org/QA/Tips/altAttribute

Text is only rendered as an image once it stops being something a browser can render as a (websafe) font. You can change the colour but once you add any effect or group it, text becomes something that can only be represented as graphic in a browser. And a non-web safe font (without any effects) will be rendered using the nearest web safe font available on the machine of the visitor.

Ok, Alt is indeed an attribute, shows my lack of knowledge.
If I understand rightly it also means that <alt text> is incorrect syntax in html, should be something like <img src="my.jpg" alt="my text">

So, I only use safe fonts but DO group text objects so if I understand correctly I do end up with an image from which web crawlers cannot deduce the content.
Is that true?

If so, I understood from a different thread that I have to use the alt attribute to assigne meaningfull text to the image so that web crawlers can get the text and my web site will score higher in ranking?

If you're using safe fonts why group the text? :)

BTW I called it ALT tag until some posts on TG put us straight in CAPITAL LETTERS ;))