1.\"
 2.\" Copyright (c) 2019 Ted Unangst
 3.\"
 4.\" Permission to use, copy, modify, and distribute this software for any
 5.\" purpose with or without fee is hereby granted, provided that the above
 6.\" copyright notice and this permission notice appear in all copies.
 7.\"
 8.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 9.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15.\"
16.Dd $Mdocdate$
17.Dt HFCS 1
18.Os
19.Sh NAME
20.Nm hfcs
21.Nd honk filtering and censorship system
22.Sh DESCRIPTION
23The honk filtering and censorship system,
24.Nm hfcs ,
25controls what messages are seen and how they are presented to the user.
26Filter rules are based on series of matches and actions.
27.Pp
28The following match types are possible.
29All criteria must match.
30.Bl -tag -width include-audience
31.It Ar who
32Match an actor or domain name.
33Matches against
34.Fa Ar actor
35property.
36.It Ar include audience
37Previous match is applied against
38.Fa to
39and
40.Fa cc
41fields as well.
42.It Ar text
43Regular expression match against the post
44.Fa content .
45.It Ar is announce
46Is announced (shared).
47.El
48.Pp
49The following actions may be applied.
50Multiple actions may be applied, but some are subsumed by others.
51.Bl -tag -width tenletters
52.It Ar reject
53Reject this message entirely.
54.It Ar skip media
55Don't include images or attachments.
56.It Ar hide
57Remove this message from most feeds.
58.It Ar collapse
59Show only a short summary with click to view content.
60.It Ar rewrite
61Rewrite message content, using
62.Ar replace
63replacement text.
64.El
65.Pp
66The
67.Ar text
68and
69.Ar rewrite
70fields are case insensitive word anchored regular expressions.
71Specifically, an argument
72.Ql re
73will be automatically rewritten as
74.Ql \\\b(?i:re)\\\b .
75.Sh SEE ALSO
76.Xr honk 1
77.Sh CAVEATS
78Not seeing is not erasing.