The university itself was loathe to see a breach of etiquette.

至于剑桥大学校方，也绝不愿见到失礼事件。

youdao

This was such a great breach of etiquette, he hardly knew what to do.

这是一起规矩的严重违反，他几乎不知所措了。

《柯林斯英汉双解大词典》

In normal times, that would be a glaring breach of Japanese corporate etiquette, but these are not normal times.

这要放在平时，显然就是公然违背日本公司礼仪。 但如今绝非“平时”。

youdao

This comment on a neighbour's internal politics was a breach of South-East Asian etiquette.

ECONOMIST: Lee Kuan Yew: an apology

The firm started a blog on social media etiquette in early 2009 when few others were willing to breach the boundary of the company intranet to focus on connecting with employees and customers.

FORBES: How to Design a Social Media Policy