To extract all matches based on a partial match, you can use use an array formula based on the INDEX and AGGREGATE functions, with support from ISNUMBER and SEARCH. In the example shown, the formula in G5 is:
=IF(F5...

To disallow input that contains one of many things, you can use a custom data validation rule based the SEARCH function.
In the example shown, the data validation applied to B5:B11 is:
=SUMPRODUCT(--ISNUMBER(SEARCH(...

To test a cell to see if contains certain words but not others, you can use an array formula based on the COUNT and SEARCH functions, wrapped in the AND function.
In the example shown, the formula in C5 is:
{=AND(...

To filter data to include data based on a "contains specific text" logic, you can use the FILTER function with help from the ISNUMBER function and SEARCH function. In the example shown, the formula in F5 is:
=FILTER(...

To check a cell for one of several things, and return the first match found in the list, you can use an INDEX / MATCH formula that uses SEARCH or FIND to locate a match. In the example shown, the formula in C5 is:
{=...

To check a cell for one of several things, and return the last match found in the list, you can use a formula based on the LOOKUP and SEARCH functions. In the case of multiple matches found, the formula will return the...

To extract text between parentheses, braces, brackets, etc. you can use a formula based on the MID function, with help from SEARCH function. In the example shown, the formula in C5 is:
=MID(B5,SEARCH("(",B5...

To categorize text using keywords with a "contains" match, you can use the SEARCH function, with help from INDEX and MATCH. In the example shown, the formula in C5 is:
{=INDEX(categories,MATCH(TRUE,ISNUMBER(SEARCH(...

To test a cell for one of many strings, while excluding others, you can use a formula based on the SEARCH, ISNUMBER, and SUMPRODUCT functions. In the example shown the formula in C5 is:
=(SUMPRODUCT(--ISNUMBER(SEARCH(...

If you want to test a cell to see if it contains all items in a list, you can do so with a formula that uses the SEARCH function, with help from the ISNUMBER, SUMPRODUCT, and COUNTA functions.
Context
Let's say you...

If you want to highlight rows in a table that contain specific text, you use conditional formatting with a formula that returns TRUE when the the text is found. The trick is to concatenate (glue together) the columns...

To get the position of the first match that does not contain a specific value, you can use an array formula based on the MATCH, SEARCH, and ISNUMBER functions. In the example shown, the formula in E5 is:
{=MATCH(FALSE...

To sum if cells contain either one text string or another (i.e. contain "cat" or "rat") you can use the SUMPRODUCT function.
Background
When you sum cells with "OR" criteria, you need to be careful not to double count...

To check if a cell contains specific text, you can use the SEARCH function together with the ISNUMBER function. In the generic version, substring is the specific text you are looking for, and text represents text in the...

If you want to test a cell to see if it contains one of several things, you can do so with a formula that uses the SEARCH function, with help from the ISNUMBER and SUMPRODUCT functions.
Context
Let's say you have a...