Ken writes:

A complete table that includes their character codes is appended below (also included are five additional characters that have vertical variants according to JIS X 0208:1997). Anyway, these can be separated into several categories of changes:

(1) o Simple rotation by 90 degrees clockwise:

￣＿―‐‖｜…‥（）〔〕［］｛｝〈〉《》「」『』【】＝

(2) o Rotate 90 degrees then flip:

ー〜

(3) o Different position in design space:

、。ぁぃぅぇぉっゃゅょゎァィゥェォッャュョヮヵヶ

These 53 characters' vertical variants is more of an industry standard. JIS X 0208-1990 specified only 24 such characters in Row 1 (the above includes 31). The 7 characters that form this discrepancy are:

￣＿―‐‖｜‥

To my surprise, JIS X 0208-1990 doesn't specify that small kana have vertical variants. JIS X 0208:1997 made further changes to JIS X 0208-1990, as follows:

o The following additional characters have vertical variants:

：―‥‘’“”

(The first and last four are in additional to the 53 specified in industry -- the second and third are in the set of 53 characters.)

o Specified that 22 small kana (10 hiragana and 12 katakana) have vertical variants.

I know that the above is probably more detail than you cared to know about, but it is complete and accurate. Regards...

-- Ken