If you download a scanned PDF (common for issues before 2000), the text is just an image. Use Adobe Acrobat Pro or a free tool like "OCR.space" to convert the scan into a searchable document. This allows you to use Ctrl+F to find every occurrence of "MACD" across 20 years of issues in seconds.
For every PDF you acquire, edit the metadata (Right-click > Properties > Details). If you download a scanned PDF (common for