First of all, this does not belong in the Client Editing Forum.
If its EOSource then maybe you should be asking over at EOSource forums? Im sure they are more knowledgeable about EOSource.
Anyways here is the Membership.ini:
# Membership config
#
# Amount = (amount)
#
# (id).MemberL1 = (id)
# (id).MemberL2 = (id)
# (id).MemberL3 = (id)
#
# Example:
#
# MemberAmount = 2
#
# 1.MemberL1 = 200
# 2.MemberL1 = 204
#
# 1.MemberL2 = 476
# 2.MemberL2 = 133
#
# 1.MemberL3 = 459
# 2.MemberI3 = 328
#
# EXP boosts.
#
# MemberEXPAmountL1 = 5%
# MemberEXPAmountL2 = 20%
# MemberEXPAmountL3 = 35%
#
# Message when a member logged in.
# MemberLoginMessage = yes
#
# The membership configuration allows you to make certain items only
# wearable for members. Which can be added with $member victim level.
#
# This way you could work with donations in exchange for certain membership
# items. There are 3 member levels which can wear different items.
#
# It is recommended to create a new file and change the config to point at it
# rather than editing this file.
#Are you using EOSource or EOServ?
Example explained. (This is how I understand it, not how it is, if u want exact instruction ask over at EOSource)
MemberAmount = 2 (This is number of items)
1.MemberL1 = 200 (L1 Means Lvl 1 Membership, 200 Is ID of the item)
2.MemberL1 = 204
1.MemberL2 = 476 (L2 Is Level 2 Membership)
2.MemberL2 = 133
1.MemberL3 = 459 (Etc.)
2.MemberI3 = 328