PDF/A is an ISO-standardized version of the Portable Document Format (PDF) specialized for use in the archiving and long-term preservation of electronic documents. PDF/A differs from PDF by prohibiting features ill-suited to long-term archiving, such as font linking (as opposed to font embedding) and encryption.[1] The ISO requirements for PDF/A file viewers include color management guidelines, support for embedded fonts, and a user interface for reading embedded annotations.
PDF/X
PDF/X is a subset of the PDF ISO standard. The purpose of PDF/X is to facilitate graphics exchange, and it therefore has a series of printing related requirements which do not apply to standard PDF files. For example, in PDF/X-1a all fonts need to be embedded and all images need to be CMYK or spot colors. PDF/X-3 accepts calibrated RGB and CIELAB colors, while retaining most of the other restrictions of PDF/X-1a.
browser test
hard drive life
tests website safety
Google’s Safe Browsing Test
https://transparencyreport.google.com/safe-browsing/search
Norton Safe Web Report
https://safeweb.norton.com
Qualys SSL Report
https://www.ssllabs.com/ssltest/index.html
Bitdefender Trafficlight
trafficlight.bitdefender.com/info?url=www.isitzen.com
Securi
https://sitecheck.sucuri.net
URLvoid Website Reputation Checker Tool
www.urlvoid.com
VirusTotal Analyze suspicious files and URLs to detect types of malware
https://www.virustotal.com/#/home/url
TRENDmicro Site Safety Center.
https://global.sitesafety.trendmicro.com
KasperskyVirusDesk Scan your file or link for viruses
https://virusdesk.kaspersky.com
avoid startup disk getting too full
boot drives need free space
avoid ninety percent full
for this less is more
1) make sure you have a backup, before any purging.
2) trash large files not needed (downloaded .dmg, installers etc.)
3) empty trash
