Part of SharedPaletteWindow, must be its own file so that Unity can serialize the scriptable object correctly.

SharedPaletteData.cs

// MIT License
// 
// Copyright (c) 2019 Sabresaurus
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
//  The above copyright notice and this permission notice shall be included in all
//  copies or substantial portions of the Software.
// 
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//  SOFTWARE.

using System;
using System.Collections.Generic;
using UnityEngine;

namespace Sabresaurus.SabreCSG
{
    /// <summary>
    /// Saved to disk so that palettes can be shared in version control
    /// </summary>
    [CreateAssetMenu]
    public class SharedPaletteData : ScriptableObject
    {
        [Serializable]
        public class TabData
        {
            public string TabName = "";
            public string TrackedString = "";
        }

        [HideInInspector] // Edited by our own window, don't expose for editing
        public List<TabData> TabDatas = new List<TabData>();
    }
}