Update User Guide to reflect inconsistency in error messages

docs/UserGuide.md

@@ -800,6 +800,7 @@ Each status type is visually distinguished in the UI: Urgent is denoted by a red
 2. **If you minimize the Help Window** and then run the `help` command (or use the `Help` menu, or the keyboard shortcut `F1`) again, the original Help Window will remain minimized, and no new Help Window will appear. The remedy is to manually restore the minimized Help Window.
 3. **When inputting names that use `/`**, this can cause an `invalid command` error to be shown or even unintended attributes for the client added. Avoid using `/`, and spell out the names in full, for cases like 'Ramesh s/o Ravichandran', change it to 'Ramesh Son Of Ravichandran' 
 4.  **Using non-english text input can cause visual bugs**. This release fully supports English text input only. Using non-English characters or text—especially those with right-to-left direction, like Arabic—may result in display problems, including incorrect text alignment, direction, and character rendering. We are actively working to expand support for international languages in future releases.
+5. **For index based commands**, negative inputs and inputs that are too large result in inconsistent error messages. We are actively working on resolving this inconsistency in future releases.
 
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