a browser is not supported
While the certification authorities certainly differ in their awareness and the appearance of their TrustLogos or SiteSeals, the most important difference is probably the browser support. You determine in which browsers the certificate of the certification authority is “held” and thus its certification is immediately recognized as trustworthy.
If a browser is not supported, the visitor can manually import the certificate of the certificate authority to recognize its certificates as trustworthy, but a visitor will rarely do so. Thus an error message appears that the certificate was signed by a certification authority, but since this authority is not known, it cannot be classified as trustworthy.
Therefore, use our recommendations to determine in which environment which certificate is best suited. Include your web statistics, if available, in your selection to find out which browsers are most frequently used and whether you can do without the unsupported browsers (percentage and absolute). You don’t lock these users out! However, you will unsettle them with the error message of “untrustworthiness” and in case of doubt you should rather choose a higher browser coverage to expect fewer visitors to have to confirm the certificate manually.