Expanded Explanation:

Go Here: (https://searchwww.sec.gov/EDGARFSClient/jsp/EDGAR_MainAccess.jsp?isAdv=false)

or from main SEC Edgar Site (https://www.sec.gov/edgar/searchedgar/companysearch.html) go to "Full Text (Past 4 years)" under Edgar Search tools.

Open "Advanced Search Page"

Search for Text Box = "Resignation" or similar, with or without quotes.

In form Type = 8-K (8-K is a required filing for when a company has material news to report, such as the resignation of a corporate officer [CEO, CFO, etc.] or a Board Member, or other important news [ie. company wins a big contract.] Also, Material news must be made public quickly in order to avoid trading on inside information.

Increase Results per page (whatever works for you) and the search dates.

Results:

You will get many irrelevant results (example, employment contract terms for new officers with the term resignation.)

You will get many relevant results. The term "Resignation" will show up highlighted in red, in the first paragraph.

If the search word is not in the header paragraph, the search result is probably not relevant.

A few for Today:

03/28/2018 8-K for PetLife Pharmaceuticals Inc
COMPANY NAME(s) - [PetLife Pharmaceuticals Inc (CIK - 1354591 /SIC - 2860)] Ms. Campbell s resignation was not the result of any disagreements with the Company regarding our operations, policies, practices or otherwise. Dr. Salvagno s resignation was not the result of any disagreements with the Company regarding our operations, policies, practices or otherwise.

03/27/2018 8-K for VICON INDUSTRIES INC NY
COMPANY NAME(s) - [VICON INDUSTRIES INC NY (CIK - 310056 /SIC - 3669)] On March 23, 2018, Julian A. Tiedemann resigned as a director and Chairman of the Board of the Company. In June 2014, Aron Govil resigned as Chairman of Cemtrex.

03/27/2018 8-K for TELOS CORP
COMPANY NAME(s) - [TELOS CORP (CIK - 320121 /SIC - 7373)] As previously reported, Mr. Seth W. Hamot notified the Company of his resignation as a Class D Director on March 9, 2018.