Copies of approved applications for farm labor contractor certificates of registration and migrant labor registration certificates, or summaries thereof, shall be supplied to the registrant by the Industrial Commissioner. The registrant shall give a copy to each worker, preferably at the time of recruitment, but in no event later than the time of arrival in this State if the worker comes from outside of the State, or the time of commencement of work if the worker does not come from outside of the State. A copy shall also be kept posted at all times in a conspicuous place in any camp in which such workers are housed.