There is no such thing as a “registration fee,” so avoid using that term. The chart of allowable fees is at https://www.edinfo.state.ia.us/web/appeals.asp?book=25&decision=62.
Fee waivers, full and partial, are governed by chapter 18 administrative rules, at http://www.legis.state.ia.us/aspx/ACODocs/DOCS/7-13-2011.281.18.pdf. A full waiver of all fees shall be granted if the student or the student’s family meets the financial eligibility criteria for free meals, for the Family Investment Program (FIP), for transportation assistance under open enrollment, or if the student is in foster care. A partial waiver is appropriate if the student or student’s family meets the financial eligibility criteria for reduced price meals, and is based on “a sliding scale related to an ability to pay.” One simple way to justify the amount of a partial waiver is to make sure that it corresponds to the percentage of the reduced price meal from full price meal. Finally, each school district has discretion to grant a temporary waiver of one or more fees in the event of a temporary financial difficulty in the student’s immediate family. This temporary waiver may be granted at any time during a school year; the maximum length of a temporary waiver shall be one year.
Q: Who is eligible for the fee waiver?
A: Per rule 281—18.3, a full waiver of all fees shall be granted if the "if the student or the student's family meets the financial eligibility criteria for free meals offered under the Child Nutrition Program, or the Family Investment Program (FIP), or transportation assistance under open enrollment provided under 281—subrule 17.9(3), or if the student is in foster care." A school district shall grant a student either a waiver of all student fees or a partial waiver of student fees if the student or the student’s family meets the financial eligibility criteria for reduced price meals offered under the Child Nutrition Program. A partial waiver shall be based on a sliding scale related to an ability to pay. Finally, at the discretion of the school district, a student may be granted a temporary waiver of a fee or fees in the event of a temporary financial difficulty in the student’s immediate family. A temporary waiver may be applied for and granted at any time during a school year. The maximum length of a temporary waiver shall be one year.
Link to chapter 18 rules: http://www.legis.state.ia.us/aspx/ACODocs/DOCS/8-25-2010.281.18.pdf
Q: On the annual list of school supplies that students are asked to bring to school, what can the district insist that a student bring and which items are optional?
A: The legal analysis of the supply list is no different from the fees issue. So, no student may be required to bring an item meant to be used by all (box of Kleenex) or by staff (cleaning products, paper towels, trash bags). These items should be marked "optional." (As a practical matter, a district cannot force a child to bring any supplies. No child should be punished for the decisions of the child's parent.)