Any business website that does not stay indexed with the search engines can be considered as useless. Penalty or Filter fixes are basically the decline in search engine rankings. Filters could be fixed in short time, but penalties take a long time to recover.
Few terms related to Search Engine Optimization when it goes blank are:
- Banning happens when there are too many session issues or miscoding. You might want to check for the broken links as well
- You could check if your contents are adding value to the readers
- Re-inclusion – when your site goes Graybar, you can apply for an appeal called re-inclusion request, preferably after making the necessary changes