When you have a license or permit from the government (the local regulatory body) to perform an excavation and keep all the records of what you are digging. You can read some permit procedures on state government websites such as Oregon, or Washington, or Massachusetts.

Unless you have the proper permission from all authorities, it is not archaeology it is looting.

The permit process will ensure that you have the proper staff and supervision in place to perform the excavation properly, and have plans in place to properly record and care for the artifacts that you excavate.

Edit: formatting.

Here´s a great old discussion on it. As kookingpot has said, a huge chunk of it has to do with permission. The rest of it is recording. To roughly quote Mythbusters, ¨If you write it down, it´s science.¨ It´s a jocular statement, but is incredibly relevant for archaeology.

    Here are past answers & discussions on this topic:

• [24 Feb. 2015 | 16 c] [Flaired Respondents | Fundamental Methodology](http://redd.it/2wzce9 "Exactly what time does the crossover occur between "GraveRobbery" and "Archeology" occur? : AskHistorians")

• [28 Feb. 2015 | 1 c] [Flaired Respondent | Artifacts in Context](http://redd.it/2xj68b "Before the advent of professional archaeology, would the people reffered to as "looters" and "robbers" of archaeology sites been transgressive criminals or simply people who happily stumbled on a cache of interesting things nobody else at the time cared about? : AskHistorians")

• [17 Mar. 2014 | 29 c] Flaired Respondents | Excavation of 20^th Century Sites

• [07 Aug. 2015 | 12 c] Flaired Respondents | Looting, Collecting, and Archaeological Ramidications

    Direct followup questions to specific flaired specialists by commenting with the question and their username with a /u/ appended to it i.e. /u/OldWorldGlory.