There might be situations where showing the recently used characters is a security issue. I suggest to add a context menu with 'Remove Character' (the selected) and 'Clear All'. The same could be done for favorites.
Starting to work on it
Fixed with the context menu providing 'Clear' and 'Clear all'. To improve the readability please rename 'Clear' to 'Remove' (and keep 'Clear all').
Akshay Deep committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=9a51e3784b2a90fd5d175424c24a89fc5775eef3 tdf#109208 Clear the list of recently used characters It will be available in 6.0.0. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.