What is the meaning of Google Translate query params?

Question

What is the meaning of all Google Translate query params?

client:t
sl:auto
tl:sk
hl:sk //language of the interface (default:en, you can try xx-bork or xx-hacker)
dt:bd
dt:ex
dt:ld
dt:md
dt:qc
dt:rw
dt:rm
dt:ss
dt:t
dt:at
dt:sw
ie:UTF-8 // encoding of the input (default: utf-8)
oe:UTF-8 // encoding of the output, the results (default: utf-8)
otf:1
srcrom:1
ssel:3
tsel:0
q:translate // query, what you type in the search box

I already discovered some of them.

Answer 1

I'm developing an online translator app, and this is what I found out empirically:

• sl - source language code (auto for autodetection)
• tl - translation language
• q - source text / word
• ie - input encoding (a guess)
• oe - output encoding (a guess)
• dt - may be included more than once and specifies what to return in the reply.

Here are some values for dt. If the value is set, the following data will be returned:

• t - translation of source text
• at - alternate translations
• rm - transcription / transliteration of source and translated texts
• bd - dictionary, in case source text is one word (you get translations with articles, reverse translations, etc.)
• md - definitions of source text, if it's one word
• ss - synonyms of source text, if it's one word
• ex - examples
• rw - See also list.
• dj - Json response with names. (dj=1)

Answer 2

Here are a few more:

• client t probably represents the standalone google translate web app (as opposed to a mobile app, or the widget that pops up if you google search "translate")
• sl is source language
• tl is translate language (the language you want to translate into)
• srcrom seems to be present when the source text has no spelling suggestions