An "ignore" button is a feature of the new version of the SMF software, among many other nifty features. However, it is on it's fifth Release Candidate version and the tech guru for Ehell, my husband, doesn't want to install a Release Candidate software version. It is taking SMF literally YEARS now to move this newest version out of beta testing and into release candidate status with no foreseeable final release date in sight. Talk about frustrating.
There are possibly modification packages that can add certain features to the current software. However, I've been very careful about what is added because not all mods are well maintained by their creators and when I occasionally update the current version of the SMF software, sometimes mod packages can fail miserably due to lack of compatibility with the newest version of forum software and there can be epic failures in forum functionality. So updating the software to the latest version means checking every mod package you have, making sure they are compatible with the latest update and hoping that when you finish the update, that everything works. Because if it doesn't, the process to correct it is painful. Switching to the new software would eliminate that problem with different mods but we'll have to wait until SMF can finally get it out of release candidacy.