a computer can be listed property if its use does meet this requirement contained in form 4562 instructions (the form where depreciation is detailed)
2. Any computer or peripheral equipment used exclusively at a regular business establishment and owned or leased by the person operating the establishment
if it doesn't meet the requirement it is listed property that is supposed to be included I part V of 4562
in addition, there is a question in part V on 24a that must be answered.
i have provided a link to 4562 instructions.
https://www.irs.gov/pub/irs-pdf/i4562.pdf
if it's listed property read the instructions starting on page 11. i think what you are referring to no longer applies. from page 12:
For other listed property (such as
computers placed in service before
2018 or video equipment), allocate the
use based on the most appropriate unit
of time the property is actually used
(rather than merely being available for
use).
the IRS gives no further guidance.
