This is not an answer to the question - it is more of an attempt to show examples how hyperlinks can work. I tried to answer some requests for clarification posted by the OP in the comments. And also this post also contains some experiments with labels of equations and linking to them.
I have made the answer community wiki. Feel free to edit it and add further explanations if needed.
To see the source, click on edit on see the revision history.
Linking to answers, questions, comments, etc.
As explained in editing help, you can use syntax such of the form [text](url)
to create links. For example, by writing [Wikipedia](http://en.wikipedia.org/wiki/)
you can link to Wikipedia.
This syntax works also in comments. When editing a post (an answer or a question), you can instead of typing this syntax click on hyperlink button or use the shortcut Ctrl+I.
This is not only for linking to post on SE network - you can link to anything what has an URL. So the only question is how to get link to a post or a comment.
- You can simply copy the link from your browser window.
- To get a link for a post, you can click on share under answer or question and copy in from there.
- To get a link to a comment, click on the timestamp. (As explained here.)
So let us try some examples:
- I can link to this question like this
[like this](http://meta.math.stackexchange.com/q/17173/)
or like this [like this](http://meta.math.stackexchange.com/questions/17173/is-there-an-option-to-refer-to-things-previously-said-anywhere-in-stackexchange)
. In the first case I obtained link by clicking on share under the question. In the second case I copied it from the browsers address bar.
- Linking to an answer is pretty much the same, for example, I can link to an answer like this or like this.
- When I click on a timestamp of some comment, I will get an url which can be used to link to the comment.
- Note that if I put link to some question in a post (like this:
http://meta.math.stackexchange.com/questions/17173/
) it will be rendered as the link where the text is the title of the question: http://meta.math.stackexchange.com/questions/17173/ (This does not work in comments, only in posts.)
Labeling equations and linking to them
I will basically repeat (and test) things from this answer
If I want to refer to some equation I can add a label to it using the following syntax.
$$x^2+y^2=z^2 \tag{P} \label{EQpyt}$$
$$x^2+y^2=z^2 \tag{P} \label{EQpyt}$$
Now if I write $\eqref{EQpyt}$
it renders as $\eqref{EQpyt}$.
Note that you may click on (P) above. You see that it brings you to this link: http://meta.math.stackexchange.com/questions/17173/is-there-an-option-to-refer-to-things-previously-said-anywhere-in-stackexchange/17192#mjx-eqn-EQpyt
You can use the same link to refer to this equation from any other site.
Let us try a different equation
$$x^3+y^3=z^3 \tag{3} \label{EQ3}$$
$$x^3+y^3=z^3 \tag{3} \label{EQ3}$$
Here is reference to it: \eqref{EQ3}. Again, we get a link which can be used when referring to this equation from another post (or another website).
[...]
immediately followed by the URL in parentheses(...)
. $\endgroup$[the first comment](http://meta.math.stackexchange.com/questions/17173/is-there-an-option-to-refer-to-things-previously-said-anywhere-in-stackexchange#comment63502_17173)
I would use syntax similar to[comment:63502_17173]
. To do that I would still need the number identifying the comment... $\endgroup$