Subfield Use When Not Using $u (URL) (856 Electronic Location and Access )
If 1st indicator = 0 (email) and a URL is not recorded in $u, the following subfields are used:
$a Host name
$f Electronic name
May also use: $b, $h, $i, $m, $n, $s, $x, $z
Unlikely to use: $c, $d, $k, $l, $o, $p, $t, $2
Those not listed can theoretically be used but no examples have been identified. This is equivalent to URL mailto: scheme.
If 1st indicator = 1 (ftp) and a URL is not recorded in $u, the following subfields are used:
$a Host name (or can use unique elements in $d and/or $f below and omit $a)
$d Path
$f Electronic name
May also use: $b, $c, $g, $i, $k, $l, $m, $n, $o, $p, $q, $s, $x, $3
Unlikely to use: $h, $t, $2
Those not listed can theoretically be used but no examples have been identified. This is equivalent to URL ftp: scheme.
If 1st indicator = 2 (Remote login) and a URL is not recorded in $u, the following subfield is used:
$a Host name
May also use: $b, $k, $l, $m, $n, $o, $p, $t, $x, $z, $3
Unlikely to use: $c, $d, $f, $g, $q, $s, $2
Those not listed can theoretically be used but no examples have been identified. This is equivalent to URL telnet: scheme.
See also:
General Information on the Use of Field 856
856 Electronic Location and Access
