Note that url and urlfrom strings aren't used in standard styles (#1358)

doc/latex/biblatex/biblatex.tex

@@ -12339,8 +12339,8 @@ \subsubsection{Localization Keys}
 The following strings are intended for use as labels, \eg\ <Address: \prm{url}> or <Abstract: \prm{abstract}>.
 
 \begin{keymarglist}
-\item[url] The term <address> in the sense of an internet address.
-\item[urlfrom] An expression like <available from \prm{url}> or <available at \prm{url}>.
+\item[url] The term <address> in the sense of an internet address. This string is not used by the standard styles.
+\item[urlfrom] An expression like <available from \prm{url}> or <available at \prm{url}>. This string is not used by the standard styles.
 \item[urlseen] An expression like <accessed on \prm{date}>, <retrieved on \prm{date}>, <visited on \prm{date}>, referring to the access date of an online resource.
 \item[file] The term <file>.
 \item[library] The term <library>.