How to convert PrintableString to BMPString?

[Gökhan AFACAN]

Hi.   I could not find enough information about converting  a PrintableString to bmpString in the Set Specification books.   While comparing BrandIds, for example, if one of brand1 and brand2 uses BMPString and the other does not (as indicated by the DER tag of each) I have to convert brand1 and / or brand2 to BMPString.   How can I convert the two different formats to each other? (PrintableString <> BMPString) How can I reach the related document?     Thank you for your interest.