VB.Net - Backreference Constructs

Backreference constructs allow a previously matched sub-expression to be identified subsequently in the same regular expression.

The following table lists these constructs −

Backreference construct	Description	Pattern	Matches
\ number	Backreference. Matches the value of a numbered subexpression.	(\w)\1	"ee" in "seek"
\k< name >	Named backreference. Matches the value of a named expression.	(?< char>\w)\k< char>	"ee" in "seek"

vb.net_regular_expressions.htm