It is important to clarify that (Character Identifier fonts, commonly used in PDFs and PostScript printing) are typically proprietary software. "F3" likely refers to a specific font collection or a CID-keyed font version (e.g., from Adobe or a Chinese/Japanese/Korean foundry).
If you need help identifying a specific “F3” font from an old PDF or software, describe the file name or sample text for further guidance. cid font f3 free download
Use the open-source alternatives above—they are modern, fully featured, and legally safe. It is important to clarify that (Character Identifier