In the help I found:

Normally a single word is selected made up of any alphanumeric character or underscore '_'.

But this is only for selecting a word. Ctrl+Right and Ctrl+Left stops at any character, which is not alphanumeric. This cannot be changed and is of course not well done.

Write a request by email to IDM, so IDM can change it in a future release. I think, IDM has simply forgotten to add '_' as word character for this function.

I also support this request for improvement of move cursor to next/previous word.

Has this issue been solved since then?
In what release?
Regards, Miklos

Since UE v13.00 there is the option Underscore is word stop for Ctrl left/right arrow at Advanced - Configuration - Editor Display - Cursor/Caret which can be enabled or disabled.

And since UE v13.10 there is a further option in the same configuration dialog named CamelCase naming stops for Ctrl left/right arrow.

Thanks Mofi,
at last I got UEStudio 09, and it works fine.
I have another question about words with underscores:
I have set up delimiters so that I can select the _part_ of word between underscores by Ctrl-DblClick.
This way I can only select one part, dragging the mouse does not extend the selection to the next part. (I often need to copy all parts but the last etc.)
Could this way of selecting a partial word work like selecting a whole word by DblClick?

Similar question: dragging after a TripleClick does not select more than one line. Why? (putty works like that, it is a good example)
I miss this, as well, but selecting on the line counter solves this.

Regards from Hungary
Miklós

We have already discussed your triple click wish here. If nobody (else) has requested that from IDM by email, you can't expect that it is implemented in the meantime.

I don't really understand your other mouse selecting wish which is obviously also not possible. Sorry, but I NEVER (really!) use the mouse for selecting text in a text editor. I have my fingers on the keyboard when writing something and therefore use the keys to select the text. I have even disabled the drag and drop text feature in UltraEdit as well as in MS Word and Total Commander. I work also daily up to 3 hours on my laptop in the train to/from work. The touchpad is disabled because too many vibrations caused wrong actions. There is no place for a mouse in the train and therefore the pointing stick is the only "mouse" I can use in the train. So I quickly learned to operate all my programs (except graphic applications) as much as possible with the keys. Working with the keys is always faster than working with the mouse when knowing all the keys of interest. That does not mean that you should learn to use the keys instead of the mouse. I have written this just for your understanding why I can't really help you here with your mouse selecting and drag and drop problems. Maybe somebody else using also the mouse often can help you.

Thanks Mofi, I agree with U on the speed of using the keyboard.
Exactly the work with underscore separated word parts is one of the main reasons for me to use the mouse:
It is quite complicated to toggle between the 2 selection modes using keys: next word or next word part (following an unserscore).
With the mouse, it is just the matter of pressing Ctrl or not.
So I am still waiting for the extendable ctrl-double-click functionality. Unless a very fast key sequence is suggested

Well, an optional parameter for UltraEdit.activeDocument.selectWord() to act as Ctrl+Double Click would be often useful.

But you don't need to wait for this enhancement. It is already possible to do this with a macro or script. See

Assign Ctrl+Double Click to keyboard
Customize 'Select Word' to include a dash as word char