770 ILCS 55/3
The person performing such labor, or furnishing such material, shall cause a notice, in writing, to be served on the president or secretary of such railroad corporation, substantially as follows, viz.:
To .... president, (or secretary, as the case may be) of the ....: You are hereby notified that I am (or have been) employed by .... as a laborer (or have furnished supplies, as the case may be) on or for the .... and that I shall hold all the property of said railroad, (or railway, as the case may be) company to secure my pay.
If there shall be a contract in writing between the original contractor and sub-contractor, material man or laborer, a copy of such contract, if the same can be obtained, shall be served with such notice and attached thereto, which notice shall be served at any time within twenty days after the completion of such sub-contract, or such labor: Provided, that no lien shall attach in favor of any person performing such labor or furnishing material until such notice shall have been served as above, or filed for record as hereinafter provided.
770 ILCS 55/3