View source for Signature block

{{Short description|Type of personalized block}}
{{for|the cryptographic verifiable proof of authorship|digital signature|}}{{For|post signing on Wikipedia|Wikipedia:Signatures}}
[[File:Email signature block example.jpg|thumb|An email signature block example, using a female variant of the [[Alan Smithee]] pseudonym.]]
A '''signature block''' (often abbreviated as '''signature''', '''sig block''', '''sig file''', '''.sig''', '''dot sig''', '''siggy''', or just '''sig''') is a personalized block of text automatically appended at the bottom of an [[email]] message, [[Usenet]] article, or [[Internet forum|forum]] post.

==Email and Usenet==
An email signature is a block of text appended to the end of an email message often containing the sender's name, address, phone number, disclaimer or other contact information.

"Traditional" internet cultural .sig practices assume the use of monospaced [[ASCII]] text because they pre-date [[MIME]] and the use of [[HTML]] in email. In this tradition, it is common practice for a signature block to consist of one or more lines containing some brief information on the author of the message such as phone number and email address, [[Uniform Resource Locator|URL]]s for sites owned or favoured by the author—but also often a quotation (occasionally automatically generated by such tools as [[fortune (program)|fortune]]), or an [[ASCII art]] picture. 
Among some groups of people it has been common to include [[:Category:Internet self-classification codes|self-classification codes]].

   |\_/|        ****************************    (\_/)
  / @ @ \       *  "Purrrfectly pleasant"  *   (='.'=)
 ( > º < )      *       Poppy Prinz        *   (")_(")
  `&gt;&gt;x&lt;&lt;´       *   (pprinz@example.com)   *
  /  O  \       ****************************
''Example of a signature block using ASCII art.''

Most email clients, including [[Mozilla Thunderbird]], Opera Mail, [[Microsoft Outlook]], [[Microsoft Outlook Express|Outlook Express]], and [[Eudora (email client)|Eudora]], can be configured to automatically append an email signature with each new message. A shortened form of a signature block (sometimes called a "signature line"), only including one's name, often with some distinguishing prefix, can be used to simply indicate the end of a [[posting style|post]] or response. Most email servers can be configured to append email signatures to all outgoing mail as well.

===Email signature generator===
An email signature generator is an app or an online web app that allows users to create a designed email signature using a pre-made template (with no need for HTML coding skills).

===Signatures in Usenet postings===
Signature blocks are also used in the [[Usenet]] discussion system.

{{quote
|<pre>...orist it's an unnecessary optimization and a (to use your words)
"performance hack", but I'm interested in a Real operating system ---
not a research toy.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Theodore Ts'o				bloom-beacon!mit-athena!tytso
308 High St., Medford, MA 02155		ty...@athena.mit.edu
   Everybody's playing the game, but nobody's rules are the same!</pre>
|''a real example from [[Theodore Ts'o]] during the [[Tanenbaum–Torvalds debate]]''<ref>[https://groups.google.com/forum/#!search/%22an$20unnecessary$20optimization$20and$20a$20(to$20use$20your$20words)%22/comp.os.minix/wlhw16QWltI/JKtu6BbqpTEJ "LINUX is obsolete"], comp.os.minix</ref><ref name=obf />
}}

===Email signatures in business===
Businesses often automatically append signature blocks to messages—or have policies mandating a certain style. Generally they resemble standard [[business card]]s in their content—and often in their presentation—with company logos and sometimes even the exact appearance of a business card. In some cases, a [[vCard]] is automatically attached.

In addition to these standard items, [[email disclaimer]]s of various sorts are often automatically appended. These are typically couched in legal jargon, but it is unclear what weight they have in law, and they are routinely lampooned.<ref>{{citation |url=https://www.economist.com/business/2011/04/07/spare-us-the-e-mail-yada-yada|newspaper=[[The Economist]] |title=Spare us the e-mail yada-yada |page=73 |date=April 9, 2011}}</ref><ref>{{citation |url=https://www.theregister.co.uk/2001/05/18/readers_letters_the_email_disclaimer/ |title=The Email Disclaimer Awards 2001 |author=Lester Haines |date=18 May 2001 |journal=[[The Register]]}}</ref>

Business emails may also use some signature block elements mandated by local laws:
* Germany requires companies to [[Impressum|disclose]] their company name, registration number, place of registration etc. in email signatures, in any business-related emails.<ref>{{cite web| url = http://theotherthomasotter.wordpress.com/2007/02/09/german-bureaucracy-coming-to-your-email-now/| title = "German bureaucracy, coming to your e-mail now"| date = 9 February 2007}}</ref>
* Ireland's [[Director of Corporate Enforcement]] requires all limited companies operating websites to disclose such information in their emails.<ref>[http://www.odce.ie/en/media_information_notices_article.aspx?article=c951ecd7-f186-41b4-bbbd-3e5d6db81d0b "Irish ODCE Information Notice I/2007/2 - Disclosure of Company Particulars in E-Communications and on Websites"] {{webarchive|url=https://web.archive.org/web/20100224073249/http://www.odce.ie/en/media_information_notices_article.aspx?article=c951ecd7-f186-41b4-bbbd-3e5d6db81d0b |date=2010-02-24 }}</ref> 
* The UK's ECommerce Regulations (reflecting EU law) require this information in all emails from limited companies.<ref>{{cite web| url = http://www.out-law.com/page-431| title = "ECommerce Regulations"|author=Pinsent Masons| date = 16 June 2023}}</ref> In England and Wales the case of Mehta v J Pereira Fernandes clarified that an [[email address]] header added to an email by the email application did not count as a signature for legal purposes, but {{quote|A party can sign a document for the purposes of Section 4 [of the [[Statute of Frauds]]] by using his full name or his last name prefixed by some or all of his initials or using his initials, and possibly by using a [[pseudonym]] or a combination of letters and numbers (as can happen for example with a Lloyds slip scratch), providing always that whatever was used was inserted into the document in order to give, and with the intention of giving, authenticity to it.<ref>Nilesh Mehta v J Pereira Fernandes SA: ChD 7 Apr 2006, quoted in Swarbrick, D., [https://swarb.co.uk/mehta-v-j-pereira-fernandes-sa-chd-7-apr-2006/ Mehta v J Pereira Fernandes SA: ChD 7 Apr 2006], updated 19 January 2022, accessed 21 January 2023</ref>}}

While criticized by some {{who|date=January 2023}} as overly bureaucratic, these regulations only extend existing laws for paper business correspondence to email.

===Standard delimiter===
{{anchor|Signature dashes}}The Usenet news system standards say that a signature block is conventionally delimited from the body of the message by a single line consisting of exactly two hyphens, followed by a space, followed by the end of line (i.e., in [[C_string_handling|C]]-[[Escape_sequences_in_C#Table_of_escape_sequences|notation]]: <code>"--&nbsp;\n"</code>).<ref>{{Cite IETF |rfc=3676 |title=The Text/Plain Format and DelSp Parameters |section=4.3 |sectionname=Usenet Signature Convention |date=February 2004 |quote=There is a long-standing convention in Usenet news which also commonly appears in Internet mail of using "-- " as the separator line between the body and the signature of a message.}}</ref><ref>[https://tools.ietf.org/html/rfc1849#section-4.3.2] RFC 1849: “Son of 1036”: News Article Format and Transmission, section 4.3 (1994, minor revisions 2010), said that "If a poster or posting agent does append a signature to an article, the signature SHOULD be preceded with a delimiter line containing (only) two hyphens (ASCII 45) followed by one blank (ASCII 32)." However, RFC 1849 was superseded by {{IETF RFC|5536|link=no}} (2009), which says nothing at all about signature blocks or delimiters.</ref><ref>[https://tools.ietf.org/html/draft-ietf-usefor-useage-01#section-3.1.2.1] "Usenet Best Practice", Usenet Format Working Group, section 3.1.2.1 (2005) said that "Whenever a poster or posting agent appends such a signature to an article, it MUST be preceded with a delimiter line containing (only) two hyphens (US-ASCII 45) followed by one SP (US-ASCII 32)." However, this document was an "Internet-Draft" and was never adopted as a standard.</ref> This latter prescription goes by many names, including “dash dash space”, "sig dashes", "signature cut line", "sig-marker", "sig separator" and "signature delimiter". It allows software to automatically mark or remove the sig block as the receiver desires.
{{quote
|<pre>-- 
Brad Templeton, publisher, ClariNet Communications Corp.         in...@clari.net
The net's #1 E-Newspaper (1,160,000 paid sbscrbrs.)  <nowiki>http://www.clari.net/brad/</nowiki></pre>
|''a real example from [[Brad Templeton]] posting in rec.humor.funny in 1995'' showing sig dashes.<ref name=obf>Note that the email address has been automatically obfuscated by Google Groups</ref><ref>[https://groups.google.com/forum/#!searchin/rec.humor.funny/1993$20brad/rec.humor.funny/zfVveummRa0/JpXw2exJmMcJ "Admin: "Internet Jokebook" price reduced to $9.95"], 02/12/1995, rec.humor.funny</ref>
}}

Most Usenet clients (including, for example, [[Mozilla Thunderbird]]) will recognize the signature block delimiter in a news article and will cut off the signature below it when inserting a quote of the original message into the composition window for a reply.  Although the Usenet standards strictly apply only to Usenet news articles, this same delimiter convention is widely used in email messages as well, and email clients (such as [[K-9 Mail|K-9]],  Opera Mail, and [[Gmail]]<ref>{{cite web| url = https://www.patronum.io/why-do-i-have-two-dashes-above-my-email-signature| title = "Guide to enabling disabling email delimiter in Gmail by the company Patronum"| date = 28 May 2022}}</ref>  commonly use it for recognition and special handling of signatures in email.

==Internet forums==
{{Main|Signature tag}}
On [[Internet forums|web forums]], the rules are often less strict on how a signature block is formatted, as [[Web browser]]s typically are not operated within the same constraints as text interface applications. Users will typically define their signature as part of their profile. Depending on the board's capabilities, signatures may range from a simple line or two of text to an elaborately constructed HTML piece. [[Image]]s are often allowed as well, including dynamically updated images usually hosted remotely and modified by a server-side script. In some cases [[Avatar (computing)#Internet forums|avatars]] or hackergotchis take over some of the role of signatures.

==FidoNet==
With [[FidoNet]], echomail and netmail software would often add an origin line at the end of a message.  This would indicate the FidoNet address and name of the originating system (not the user).  The user posting the message would generally not have any control over the origin line.  However, single-line [[tagline]]s, added under user control, would often contain a humorous or witty saying.  Multi-line user signature blocks were rare.

However, a tearline standard for FidoNet was included in FTS-0004<ref>{{cite web| url = http://www.ftsc.org/docs/fts-0004.001| title = "FidoNet EchoMail Specification"}}</ref> and clarified in FSC-0068<ref>{{cite web| url = http://www.ftsc.org/docs/fsc-0068.001| title = "A Proposed Replacement For FTS-0004"}}</ref> as three dashes optionally followed by a space optionally followed by text.

==See also==

*[[Acknowledgment (creative arts and sciences)]]
*[[Attribution (copyright)]]
*[[Byline]]
*[[Credit (creative arts)]]
*[[James Parry (Usenetter)|Kibo]], a Usenet poster famous for his absurdly long signature

==Notes and references==
<references/>

==External links==
* {{IETF RFC|1855|link=no}}, "Netiquette Guidelines" (section 2.1.1 contains guidelines on mail)
* {{IETF RFC|3676|link=no}}, (4.3 Usenet Signature Convention)
* [https://web.archive.org/web/20060621203857/http://lipas.uwasa.fi/~ts/http/signatur.html What are the restrictions for a proper signature?]
* [https://web.archive.org/web/20070318102813/http://www.odce.ie/GetAttachment.aspx?id=6b7d40ce-d830-4613-bc9f-eb7ae501db93 Information Release from Ireland's ODCE (pdf)]

[[Category:Internet culture]]
[[Category:Internet forum terminology]]
[[Category:Signature]]