Can one offset accrued short term bond gain but short term loss on other sales? Sorry- needed to edit but could not

Fidelity, on its tax reporting page for planning purposes, calculates one's ongoing short and long term losses over the year and includes accrued market discount gains there rather than in interest income, where realized OID gains are generally reported. I have seen some sites where accrued market discount gains on bonds, in my case Treasuries, can be reported as short or long term capital gains- for example on Fastercapital.com oid.png

However, it's not clear to me whether this is actually true; if it is how would one report in TT the offset of short term loss of sales of T bonds/notes against the accrued discount of matured short term gains or is it simply treated like OID? IRS Pub 1212 is not helpful on this point. 

 

Thanks