Ask your employer. Employers make up their own abbreviations for many of the things shown in box 14.
This is an old story, several years running. From back in at least 2019..or earlier:
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Some but not all providers are putting two transit tax $$ amounts in box 14 of a W-2. They appear to be indicating "something like" :
ORSTTW = Oregon Statewide Transit Tax "Wages"
ORSTTT (or in your case ORSTT W/H)= Oregon Statewide Transit Tax (or actual withholding as indicated by the W/H)
For these two entries (if both are present) the correct tax "Category" must be chosen.
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In box 14 of your W-2:
1) For the lower $$ amount use the "Category" Oregon Statewide Transit Tax
2) If you have a second Oregon entry in box 14, which is a much larger amount ....those are OR wages... (an amount that may be the same as, or close to your actual Oregon wages for the year) my personal opinion is that they should not be listed at all...but for those select "Other not on above list".
The "default" Category selection that the software might make, could be wrong, and that could cause problems if improperly categorized
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