systemd/man/less-variables.xml

<?xml version="1.0"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
                 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">

<refsect1>
        <title>Environment</title>

        <variablelist class='environment-variables'>
                <varlistentry id='pager'>
                        <term><varname>$SYSTEMD_PAGER</varname></term>

                        <listitem><para>Pager to use when
                        <option>--no-pager</option> is not given;
                        overrides <varname>$PAGER</varname>.  Setting
                        this to an empty string or the value
                        <literal>cat</literal> is equivalent to passing
                        <option>--no-pager</option>.</para></listitem>
                </varlistentry>

                <varlistentry id='less'>
                        <term><varname>$SYSTEMD_LESS</varname></term>

                        <listitem><para>Override the default
                        options passed to
                        <command>less</command>
                        (<literal>FRSXMK</literal>).</para></listitem>
                </varlistentry>
        </variablelist>
</refsect1>