在体育比赛参赛须知中 NF NOC 是什么意思？

如果NF 和NOC 是并列的话，那
NF=国家联盟 National Federation

NOC =各国奥委会

下面的资料给你参考：
If a National Federation/NOC enters. only one swimmer per event all swimmers entered must meet the qualifying B standard time. ... Should an NF/NOC not enter a qualified athlete, the unused quota place will be transferred to the next