短期intern工作簽證？ - 留學

請問有沒有人在英國當intern的經驗？
我在ukvisas.gov.uk找到的資訊如下

Do I need a UK visa?
YES
You will normally need a visa (and a Certificate of Sponsorship)
to come to the United Kingdom to work.
However, if you are coming to the United Kingdom as a work permit holder
for 6 months or less, or as a Temporary Worker in the Creative and
Sporting Category of PBS Tier 5 for less than 3 months,
you will not require a visa.

我目前在美國念書 這個暑假找到在英國公司的實習三個月的機會
不知道有沒有人有類似的經驗能分享？ 要怎樣才算是work permit holder呢？

謝謝！

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