If a context menu is raised on selected text, the following menu items are displayed:
Run occur command to show occurrences of selected text.
Applies mode-specific markup to emphasize the selected text (e.g. bold, italic, code, etc.).
org-mode and markdown-mode.
Applies transforms (upper/lower case, capitalize) to the selected text.
Run query-replace on selected text.
Run query-replace-regexp on selected text.
Toggles selected text to be commented based on mode.
prog-mode and org-mode
Writes selected text to a user-specified file.
If a word is selected, uses dictionary to look up its definition.
If the current buffer is using Org mode, then this sub-menu is displayed. Learn more about this in Org “Copy as…” Context Menu.