Under Skype, upon making a copy/paste from one conversation windows to another the contents will be quoted.
You can configure Skype to paste these contents as plain text.
- Click Tools > Options > IM & SMS > "Show advanced options" button.
- In the IM settings window, go to the "Pressing CTRL + V will" section.
- Check the "Paste message as plain text" option.
- Click on Save to validate.