Answer
PDF/A is an archival-focused ISO-standardized PDF variant that disallows certain features unfit for long-term preservation (like font linking instead of embedding, and encryption); enabling this parameter makes IFS-generated reports comply with that standard, mainly relevant if you actually rely on PDF/A signing somewhere downstream. Turning it off simply means reports relying on PDF/A signing can no longer use that functionality — it doesn't otherwise degrade normal report output. It does add some processing overhead to the Report Formatter, and there have been cases (observed specifically with Crystal Reports) where enabling this parameter without actually using PDF/A signing caused report-generation errors — so if PDF/A signing isn't a genuine requirement, it's generally safer to leave this parameter off. Also worth noting: enabling it only makes IFS's own output partially PDF/A-conformant and may not pass validation from independent third-party PDF/A compliance checkers.