Update adding-synonyms.md

Made the list of disallowed special characters more prominent.

Author: shshubhe

articles/cognitive-services/language-service/question-answering/tutorials/adding-synonyms.md

@@ -76,12 +76,36 @@ As you can see, when `troubleshoot` was not added as a synonym, we got a low con
 > [!IMPORTANT]
 > Synonyms are case insensitive. Synonyms also might not work as expected if you add stop words as synonyms. The list of stop words can be found here: [List of stop words](https://github.com/Azure-Samples/azure-search-sample-data/blob/master/STOPWORDS.md).
 > For instance, if you add the abbreviation **IT** for Information technology, the system might not be able to recognize Information Technology because **IT** is a stop word and is filtered when a query is processed.
-> Synonyms do not allow these special characters: ',', '?', ':', ';', '\"', '\'', '(', ')', '{', '}', '[', ']', '-', '+', '.', '/', '!', '*', '-', '_', '@', '#' 
 
 ## Notes
 * Synonyms can be added in any order. The ordering is not considered in any computational logic.
-* Special characters are not allowed for synonyms. For hyphenated words like "COVID-19", they are treated the same as "COVID 19", and "space" can be used as a term separator.
 * In case of overlapping synonym words between 2 sets of alterations, it may have unexpected results and it is not recommended to use overlapping sets.
+* Special characters are not allowed for synonyms. For hyphenated words like "COVID-19", they are treated the same as "COVID 19", and "space" can be used as a term separator. Following is the list of special characters **not allowed**:
+
+|Special character | Symbol|
+|--------------|--------------------------------|
+|Comma | ,|
+|Question mark | ?|
+|Colon| :|
+|Semicolon| ;|
+|Double quotation mark| \"|
+|Single quotation mark| \'|
+|Open parenthesis|(|
+|Close parenthesis|)|
+|Open brace|{|
+|Close brace|}|
+|Open bracket|[|
+|Close bracket|]|
+|Hyphen/dash|-|
+|Plus sign|+|
+|Period|.|
+|Forward slash|/|
+|Exclamation mark|!|
+|Asterisk|\*|
+|Underscore|\_|
+|Ampersand|@|
+|Hash|#|
+
 
 ## Next steps