When writing in some formal Japanese CV (学歴/職歴), it is common to be asked to put each job/university/etc. on a single dated line, with a second line to indicate when one quit/graduated/dropped-out/etc. E.g:
平成２０年 ４月 １日 東京大学情報学部入学
平成２４年 ３月３１日 同上卒業
平成２４年 ４月 １日 松下電器産業株式会社入社
University enrollment will be 入学/卒業, post-grad would be 進学/卒業, job would be 入社/退社...
My question is then:
What is a proper equivalent to indicate a research internship?
That is a non-paying, temporary research position in a public (government-run) lab facility that is not a university (国立研究所). In such a case, it seems that both 入社 and 入学 would not fit. 入所 sounds like it might be a possibility, but also may be a complete mistranslation (since the word also exists for completely different situations).
I would welcome any suggestions, (preferably) with pointers to approved examples or other authoritative sources...