diff --git a/SabreTools.Library/DatFiles/DatHeader.cs b/SabreTools.Library/DatFiles/DatHeader.cs
index 99d57f29..17f1670f 100644
--- a/SabreTools.Library/DatFiles/DatHeader.cs
+++ b/SabreTools.Library/DatFiles/DatHeader.cs
@@ -215,6 +215,34 @@ namespace SabreTools.Library.DatFiles
 
         #endregion
 
+        #region OfflineList Fields
+
+        /// <summary>
+        /// System
+        /// </summary>
+        [JsonProperty("system")]
+        public string System { get; set; }
+
+        /// <summary>
+        /// Screenshots width
+        /// </summary>
+        [JsonProperty("screenshotswidth")]
+        public string ScreenshotsWidth { get; set; }
+
+        /// <summary>
+        /// Screenshots height
+        /// </summary>
+        [JsonProperty("screenshotsheight")]
+        public string ScreenshotsHeight { get; set; }
+
+        /// <summary>
+        /// Rom title
+        /// </summary>
+        [JsonProperty("romtitle")]
+        public string RomTitle { get; set; }
+
+        #endregion
+
         #region Write pre-processing
 
         /// <summary>
diff --git a/SabreTools.Library/DatFiles/Json.cs b/SabreTools.Library/DatFiles/Json.cs
index c0746eb6..1e5676ae 100644
--- a/SabreTools.Library/DatFiles/Json.cs
+++ b/SabreTools.Library/DatFiles/Json.cs
@@ -236,6 +236,30 @@ namespace SabreTools.Library.DatFiles
 
                     #endregion
 
+                    #region OfflineList
+
+                    case "system":
+                        content = jtr.ReadAsString();
+                        Header.System = (Header.System == null ? content : Header.System);
+                        break;
+
+                    case "screenshotswidth":
+                        content = jtr.ReadAsString();
+                        Header.ScreenshotsWidth = (Header.ScreenshotsWidth == null ? content : Header.ScreenshotsWidth);
+                        break;
+
+                    case "screenshotsheight":
+                        content = jtr.ReadAsString();
+                        Header.ScreenshotsHeight = (Header.ScreenshotsHeight == null ? content : Header.ScreenshotsHeight);
+                        break;
+
+                    case "romtitle":
+                        content = jtr.ReadAsString();
+                        Header.RomTitle = (Header.MameConfig == null ? content : Header.RomTitle);
+                        break;
+
+                    #endregion
+
                     default:
                         break;
                 }
@@ -1042,6 +1066,34 @@ namespace SabreTools.Library.DatFiles
 
                 #endregion
 
+                #region OfflineList
+
+                if (!string.IsNullOrWhiteSpace(Header.System))
+                {
+                    jtw.WritePropertyName("system");
+                    jtw.WriteValue(Header.System);
+                }
+
+                if (!string.IsNullOrWhiteSpace(Header.ScreenshotsWidth))
+                {
+                    jtw.WritePropertyName("screenshotswidth");
+                    jtw.WriteValue(Header.ScreenshotsWidth);
+                }
+
+                if (!string.IsNullOrWhiteSpace(Header.ScreenshotsHeight))
+                {
+                    jtw.WritePropertyName("screenshotsheight");
+                    jtw.WriteValue(Header.ScreenshotsHeight);
+                }
+
+                if (!string.IsNullOrWhiteSpace(Header.RomTitle))
+                {
+                    jtw.WritePropertyName("romtitle");
+                    jtw.WriteValue(Header.RomTitle);
+                }
+
+                #endregion
+
                 // End header
                 jtw.WriteEndObject();
 
diff --git a/SabreTools.Library/DatFiles/OfflineList.cs b/SabreTools.Library/DatFiles/OfflineList.cs
index 60e87a17..c316a639 100644
--- a/SabreTools.Library/DatFiles/OfflineList.cs
+++ b/SabreTools.Library/DatFiles/OfflineList.cs
@@ -138,17 +138,23 @@ namespace SabreTools.Library.DatFiles
                         break;
 
                     case "system":
-                        reader.ReadElementContentAsString();
+                        content = reader.ReadElementContentAsString();
+                        Header.System = (Header.System == null ? content : Header.System);
                         break;
 
+                    // TODO: Int32?
                     case "screenshotswidth":
-                        reader.ReadElementContentAsString(); // Int32?
+                        content = reader.ReadElementContentAsString();
+                        Header.ScreenshotsWidth = (Header.ScreenshotsWidth == null ? content : Header.ScreenshotsWidth);
                         break;
 
+                    // TODO: Int32?
                     case "screenshotsheight":
-                        reader.ReadElementContentAsString(); // Int32?
+                        content = reader.ReadElementContentAsString();
+                        Header.ScreenshotsHeight = (Header.ScreenshotsHeight == null ? content : Header.ScreenshotsHeight);
                         break;
 
+                    // TODO: Use header values
                     case "infos":
                         ReadInfos(reader.ReadSubtree());
 
@@ -156,6 +162,7 @@ namespace SabreTools.Library.DatFiles
                         reader.Skip();
                         break;
 
+                    // TODO: Use header values
                     case "canopen":
                         ReadCanOpen(reader.ReadSubtree());
 
@@ -163,6 +170,7 @@ namespace SabreTools.Library.DatFiles
                         reader.Skip();
                         break;
 
+                    // TODO: Use header values
                     case "newdat":
                         ReadNewDat(reader.ReadSubtree());
 
@@ -170,6 +178,7 @@ namespace SabreTools.Library.DatFiles
                         reader.Skip();
                         break;
 
+                    // TODO: Use header values
                     case "search":
                         ReadSearch(reader.ReadSubtree());
 
@@ -178,7 +187,8 @@ namespace SabreTools.Library.DatFiles
                         break;
 
                     case "romtitle":
-                        reader.ReadElementContentAsString();
+                        content = reader.ReadElementContentAsString();
+                        Header.RomTitle = (Header.RomTitle == null ? content : Header.RomTitle);
                         break;
 
                     default:
@@ -840,9 +850,9 @@ namespace SabreTools.Library.DatFiles
                 xtw.WriteStartElement("configuration");
                 xtw.WriteElementString("datName", Header.Name);
                 xtw.WriteElementString("datVersion", Items.TotalCount.ToString());
-                xtw.WriteElementString("system", "none");
-                xtw.WriteElementString("screenshotsWidth", "240");
-                xtw.WriteElementString("screenshotsHeight", "160");
+                xtw.WriteElementString("system", Header.System ?? string.Empty);
+                xtw.WriteElementString("screenshotsWidth", Header.ScreenshotsWidth ?? string.Empty);
+                xtw.WriteElementString("screenshotsHeight", Header.ScreenshotsHeight ?? string.Empty);
 
                 xtw.WriteStartElement("infos");
 
@@ -985,7 +995,7 @@ namespace SabreTools.Library.DatFiles
                 // End search
                 xtw.WriteEndElement();
 
-                xtw.WriteElementString("romTitle", "%u - %n");
+                xtw.WriteElementString("romTitle", Header.RomTitle ?? "%u - %n");
 
                 // End configuration
                 xtw.WriteEndElement();
diff --git a/SabreTools.Library/DatFiles/SeparatedValue.cs b/SabreTools.Library/DatFiles/SeparatedValue.cs
index 8d55e357..603dcf32 100644
--- a/SabreTools.Library/DatFiles/SeparatedValue.cs
+++ b/SabreTools.Library/DatFiles/SeparatedValue.cs
@@ -208,6 +208,26 @@ namespace SabreTools.Library.DatFiles
 
                         #endregion
 
+                        #region OfflineList
+
+                        case "DatFile.System":
+                            Header.System = (Header.System == null ? value : Header.System);
+                            break;
+
+                        case "DatFile.ScreenshotsWidth":
+                            Header.ScreenshotsWidth = (Header.ScreenshotsWidth == null ? value : Header.ScreenshotsWidth);
+                            break;
+
+                        case "DatFile.ScreenshotsHeight":
+                            Header.ScreenshotsHeight = (Header.ScreenshotsHeight == null ? value : Header.ScreenshotsHeight);
+                            break;
+
+                        case "DatFile.RomTitle":
+                            Header.RomTitle = (Header.RomTitle == null ? value : Header.RomTitle);
+                            break;
+
+                        #endregion
+
                         #endregion // DatFile
 
                         #region Machine
@@ -766,6 +786,34 @@ namespace SabreTools.Library.DatFiles
 
                 #endregion
 
+                #region OfflineList
+
+                case "system":
+                    return "DatFile.System";
+
+                case "screenshotwidth":
+                case "screenshotswidth":
+                case "screenshot width":
+                case "screenshot-width":
+                case "screenshots width":
+                case "screenshots-width":
+                    return "DatFile.ScreenshotsWidth";
+
+                case "screenshotheight":
+                case "screenshotsheight":
+                case "screenshot height":
+                case "screenshot-height":
+                case "screenshots height":
+                case "screenshots-height":
+                    return "DatFile.ScreenshotsHeight";
+
+                case "romtitle":
+                case "rom title":
+                case "rom-title":
+                    return "DatFile.RomTitle";
+
+                #endregion
+
                 #endregion // DatFile
 
                 #region Machine