dan , 2 hours ago

From that RFC:

<span style="color:#323232;">0.0.0.0/8 - Addresses in this block refer to source hosts on "this"
</span><span style="color:#323232;">network.  Address 0.0.0.0/32 may be used as a source address for this
</span><span style="color:#323232;">host on this network; other addresses within 0.0.0.0/8 may be used to
</span><span style="color:#323232;">refer to specified hosts on this network ([RFC1122], Section
</span><span style="color:#323232;">3.2.1.3).
</span>

(note that it only says “source address”)

which was based on RFC 1122, which states:

<span style="color:#323232;">We now summarize the important special cases for Class A, B,
</span><span style="color:#323232;">and C IP addresses, using the following notation for an IP
</span><span style="color:#323232;">address:
</span><span style="color:#323232;">
</span><span style="color:#323232;">    { <Network-number>, <Host-number> }
</span><span style="color:#323232;">
</span><span style="color:#323232;">or
</span><span style="color:#323232;">    { <Network-number>, <Subnet-number>, <Host-number> }
</span><span style="color:#323232;">
</span><span style="color:#323232;">...
</span><span style="color:#323232;">
</span><span style="color:#323232;">(a)  { 0, 0 }
</span><span style="color:#323232;">
</span><span style="color:#323232;">This host on this network.  MUST NOT be sent, except as
</span><span style="color:#323232;">a source address as part of an initialization procedure
</span><span style="color:#323232;">by which the host learns its own IP address.
</span><span style="color:#323232;">
</span><span style="color:#323232;">See also Section 3.3.6 for a non-standard use of {0,0}.
</span>

(section 3.3.6 just talks about it being a legacy IP for broadcasts - I don’t think that even works any more)