Many mobile cards often contain two or more adjacent counties from a substantial road trip. These cards often resemble plain index cards, and thus do not have much eye appeal. Short-wave QSL cards often resemble ordinary ham QSL cards, but are scarce enough to warrant a premium of about one dollar. For the others, you need to inspect the frequency information, if given. Wavelengths between 10 and 100 meters is yet another way short-wave may be expressed on these cards.
Early cards use the abbreviation mc instead of MHz.
However, QSL cards and their more modern POMA variants are specialties of ours. So you can click these hyperlinks to view current priced lots accompanied by numerous full-color illustrations. We also have many cards offered individually in the US state listings.