I use the benchmark lign that I "take" beside the rule.
Then I move it to the text I need to align with an other.
The problem is that the lign dissapears
I would like that a green lign appears and remains as benchmark
I should have made something wrong, but I don't get what.
Thank you for your help
One possible situation could be that you are in Preview mode. It causes guides to disappear. Can you put the document back in Normal view (this is two buttons at the bottom of the Tool panel)?
Thank you but is doesn't chnage anything. I still to get a permanent green lign.
In both cases (preview and normal view), I see the benchmarks but the lign dissapears afterwards.
Not quite sure how you are creating the "green line", but it sounds like you might be using ruler guides. If that's the case, make sure that View > Grids & Guides is set to Show Guides. It's a little confusing because when that is turned on, the menu wording says "Hide Guides". The keyboard shortcut Ctrl/Cmd + ; will toggle between Show/Hide.
Ruler guides also reside on layers, so if you have more than one layer in your document, turning off the layer they're on will hide the guides.
Also, there is a zoom level setting for ruler guides that causes them to disappear when zooming out. You can control that by selecting the ruler guide(s) with the Selection Tool and choosing Layout > Ruler Guides... . The number determines the smallest percentage where they're still visible. If it's set to 75%, as soon as you zoom out to 74%, they will disappear.