Revise spell check modes

Author: MikeDodaro

articles/cognitive-services/Bing-Spell-Check/proof-text.md

@@ -30,7 +30,19 @@ This spell-checker can handle any word-processing scenario:
 
 ## Spell check modes
 
-The API supports two proofing modes, Proof and Spell. The default mode is Proof. The Proof spelling mode provides the most comprehensive checks, but it's available only in the en-US (English-United States) market. For all other markets, set the [mode](https://docs.microsoft.com/rest/api/cognitiveservices/bing-spell-check-api-v7-reference#mode) query parameter to Spell. The Spell mode finds most spelling mistakes but doesn't find some of the grammar errors that Proof catches (for example, capitalization and repeated words).
+The API supports two proofing modes, `Proof` and `Spell`.  Try examples [here](https://azure.microsoft.com/en-us/services/cognitive-services/spell-check/).
+### Proof - for documents scenario
+The default mode is `Proof`. The `Proof` spelling mode provides the most comprehensive checks,  adding capitalization, basic punctuation, and other features to aid document creation. but it is available only in the en-US (English-United States), es-ES(Spanish), pt-BR(Portuguese) markets (Note: only in beta version for Spanish and Portuguese). For all other markets, set the mode query parameter to Spell. 
+•	Note:  If the length of query text exceeds 4096, it will be truncated to 4096 characters, then get processed. 
+### Spell -  for web searches/queries scenario
+`Spell` is more aggressive in order to return better search results. The `Spell` mode finds most spelling mistakes but doesn't find some of the grammar errors that `Proof` catches, for example, capitalization and repeated words.
+•	Note: The max query length supported is as below. If query exceed the bound, the result appears that the query is not altered.
+o	130 characters for language code of en, de, es, fr, pl, pt, sv, ru, nl, nb, tr-tr, it, zh, ko. 
+o	65 characters for others
+
+## Market setting
+Market needs to be specified in the query parameter in request URL, otherwise speller will take the default market based on IP address.
+
 
 ## POST vs. GET