diff --git a/hsarback/src/de/hsadmin/mods/pac/Pac.java b/hsarback/src/de/hsadmin/mods/pac/Pac.java
index 4fa5ef0..b3969d6 100644
--- a/hsarback/src/de/hsadmin/mods/pac/Pac.java
+++ b/hsarback/src/de/hsadmin/mods/pac/Pac.java
@@ -25,7 +25,9 @@ import javax.persistence.Temporal;
 import javax.persistence.TemporalType;
 
 import de.hsadmin.core.model.AbstractEntity;
+import de.hsadmin.core.model.AnnFieldIO;
 import de.hsadmin.core.model.AnnModuleImpl;
+import de.hsadmin.core.model.ReadWriteAccess;
 import de.hsadmin.hostsharing.BasePacType;
 import de.hsadmin.mods.cust.Customer;
 import de.hsadmin.mods.user.UnixUser;
@@ -46,6 +48,7 @@ public class Pac extends AbstractEntity implements Serializable {
 	private long id;
 
 	@Column(name = "packet_name", unique = true)
+	@AnnFieldIO(rw=ReadWriteAccess.WRITEONCE,validation="[a-z0-9]*")
 	private String name;
 
 	@JoinColumn(name = "bp_id")
@@ -54,10 +57,12 @@ public class Pac extends AbstractEntity implements Serializable {
 
 	@JoinColumn(name = "basepacket_id")
 	@ManyToOne(fetch = EAGER)
+	@AnnFieldIO(rw=ReadWriteAccess.WRITEONCE,validation="[A-Za-z0-9\\/]*")
 	private BasePac basePac;
 
 	@JoinColumn(name = "hive_id")
 	@ManyToOne(fetch = EAGER)
+	@AnnFieldIO(rw=ReadWriteAccess.WRITEONCE,validation="[a-z0-9]*")
 	private Hive hive;
 
 	@Column(name = "created")
@@ -73,6 +78,7 @@ public class Pac extends AbstractEntity implements Serializable {
 	
 	@JoinColumn(name = "cur_inet_addr_id", nullable = true)
 	@ManyToOne(fetch = EAGER)
+	@AnnFieldIO(rw=ReadWriteAccess.WRITEONCE,validation="[0-9\\.]*")
 	private INetAddress curINetAddr;
 
 	@JoinColumn(name = "old_inet_addr_id", nullable = true)
@@ -83,6 +89,7 @@ public class Pac extends AbstractEntity implements Serializable {
 	private Set<PacComponent> pacComponents;
 
 	@OneToMany(fetch = LAZY, cascade = ALL, mappedBy="pac")
+	@AnnFieldIO(rw=ReadWriteAccess.WRITEONCE,validation="[a-z0-9\\-\\.\\_]*")
 	private Set<UnixUser> unixUser;
 
 	public void initPacComponents(EntityManager em, BasePac aBasepac, boolean setDefaults) {