These gray warning words after deletion, won't appear,
Excuse me what method can let these words appear again?

I know there is a show parameter name hints on completion option, but this option is only new input code is prompt,
But after my needs is prompt the text to be deleted, how to display,

Tip for example I can delete all the text deleted, after two weeks, I once again open the code, how to set up to make the Suggestions words appear?
Thank you very much!