precaution= something that is done to prevent possible harm or trouble from happening in the future.
Every home owner should take precautions against fire. against介词短语应该是precautions的定语。
COCA例句:
and in any case precautions against such interruptions had been taken. 很显然,against介词短语是precautions的定语。
网友这个句子中,against介词短语为主语precaution的定语,为了避免句子头重脚轻,介词短语后移到句末,形成分隔式定语。