# What is a clearsigned message?

PGP Digital Timestamping Service webpage mentions

The service operates in a number of different "modes" depending upon the required results. The current modes are:-

post: forwarding an outbound message with a proof of posting certificate
clear: the received message is clearsigned and returned to the sender
text: the received message is signed and returned ASCII armoured to the sender
pgp: the received message (which must be ASCII armoured) is assumed to be a PGP file which is then signed and returned to the sender
binary: the received message (which must be ASCII armoured) is assumed not to be a PGP file which is then signed and returned to the sender


What is a clearsigned message? I searched around quite a bit using Duck Duck Go, and on this site but I couldn't find an explanation.

From dictionary.university with search clearsigned definition

1. Dictionary of Internet Terms A digitally signed S/MIME or PGP message in which the content of the message is readable even if the signature is not.
1. A message that is digitally signed but not encrypted.

• Cleartext is readable data transmitted or stored “in the clear” (i.e. unencrypted)

• Plaintext is the input to an encryption algorithm

• Ciphertext is the unreadable output of an encryption algorithm

• Plain text means its text that hasn’t been formatted (i.e., a plain text file)

Note that plain text might be an ambiguous term without context. See the commnets.

• "Plain Text" is ambiguous. It might be US ASCII. It might be Unicode in UTF-8. It might be Unicode in UCS-2 (Microsoft Windows). It might be ISO/IEC 8859-1:1998 Latin-1. It's probably Unicode these days, most commonly UTF-8. But the old formats still exist, and can be problematic when someone in the US wants "plain text" meaning US English without accents and rejects text in other languages. May 27 at 12:49
• @SAIPeregrinus It is more about higher level, In computing, plain text is a loose term for data (e.g. file contents) that represent only characters of readable material but not its graphical representation nor other objects (floating-point numbers, images, etc.). May 27 at 14:50
• Yep, but people confuse the (many) uses op the term. EG emoji are "Plain Text" to Unicode, despite being displayed as images to the user. Egyptian heiroglyphs like 𓃤 are plain text. Playing cards like 🂼 are plain text. The "Control Pictures" plane is a set of pictures, but still text. You can use Unicode to write "rich text" English like 𝗯𝗼𝗹𝗱 or 𝘪𝘵𝘢𝘭𝘪𝘤 in "plain text". Etc. Even in ASCII the non-printable control characters are "plain text" despite not being human-readable. It's an ambiguous term, the meaning depends on the encoding. May 27 at 15:07
• It really depends on the context, I've put it since there is a distinction between plain text and plaintext. Usually, the compound word later combined in English ( at least American English). Like on-line now online. In this case, the meaning a bit different, that was my point. If you really consider that is confusing, I can simply delete it. May 27 at 15:11
• I don't think that part is confusing. "Plaintext“ is a well-defined term, though it doesn't have anything to do with text. "Plain Text" is not well-defined or even fully definable. A bit like "char" being a C type of at least 8 bits, vs "character" being an ambiguous element of some written communication system. It's worth making the distinction, and worth warning people against using the ambiguous terms. May 27 at 15:26